News

Baby on the way!

29th August 2010
My wife and I are expecting our first baby on the 1st September. This means I will not be able to take any calls or work from this date for a short period. I will be available via email at repair@prscardiff.co.uk for questions and arrangements for picking up or dropping off of equipment, which will have to be done at our convenience. Normal service will resume and be announced here when things are more settled.

Hewlett Packard HP550 laptop

28th August 2010
Laptop would not power on or charge. Cause was broken power plug - a replacement fixed the computer.

Vestax PMC-06Pro mixer

26th August 2010
The mixer would not power on. This was due to broken insulation around the grommet on the power brick. The faulty cable was removed and replaced allowing the mixer to be turned on. The headphone mix fader was faulty - this was removed and reconditioned bringing the mixer back to good working order.

Sennheiser EM100 radio microphone

24th August 2010
The microphone was making very loud banging noises when shaken. This was due to cracked solder and loose screening cans inside the microphone due to impact. The damage was repaired and the mic returned to good working order.

Kenwood TK-3101 PMR radio

22nd August 2010
Another radio used on a motorbike where the unit had to be stored underneath the seat, limiting its range. A BNC socket was fitted in place of the old antenna so a good external one could be attached.

Alesis M1 MKII active monitor speaker

21st August 2010
The switched mode power supply inside had died, blowing the 5A internal fuse. The causes were: 1) Fixing glue of the wrong type which had gone conductive over time, shorting out whatever it came into contact with. 2) The PSU recifiers had blown. 3) The main PSU capacitors had also failed and were swollen and had leaked electrolyte. 4) A surge protector had also shorted out. All of these components were replaced, the glue removed and the PCB repaired where glue had eaten into the board and charred from the later short circuit. The speaker was returned to good working order.

Alesis M1 MKII active monitor speaker

21st August 2010
The other speaker has suffered a similar fate to the one above. Additionally, some 1N4148 diodes had also died and there was more severe damage to the PCB which was cleaned up. The speaker was returned to good working order.

Stageline STA-322 1200W amplifier

15th August 2010
The amplifier was indicating overheat and protect after use. The reason was failure of a 24V fan cooling the amplifier module. A replacement restore cooling and proper operation of the amplifier.

B&W CDM-02 high end speakers

15th August 2010
Unfortunately, the bass woofer in these nice speakers had blown. B&W do not make or supply the replacement speakers anymore, so a high quality 100W RMS woofer was fitted and the fascia trim modified so that it fitted nicely on the new speaker and looked like a good job. Apart from the black cone, the speaker sounded identical to the original and the customer was happy with the work.

Pioneer CDJ1000 MK3 CD deck

14th August 2010
The deck was skipping and freezing. The CD pickup was cleaned, but the problem remained after some time playing a CD. A replacement optical pickup was ordered next day delivery and fitted, curing the fault - just in time for the customer's club night on Saturday.

Pioneer CDJ1000 MK1 CD deck

9th August 2010
Sadly another case of an ebay seller supplying faulty goods. The customer bought a CDJ1000 however the unit that arrived was dead down one side. The customer sent it back and received another unit that almost worked except the jog dial didn't. The cause was initially traced to a faulty optoelectronic sensor, but after replacement it was discovered that an I/O line on the System Control Processor IC had failed and was holding the line low. This meant either a costly new main board at over £400 or try to get a replacement IC. Luckily the IC is stocked by Pioneer so one was ordered and fitted which repaired the deck. The IC is a high density surface mount component which was replaced using specialised equipment here at PRS. The deck was returned to good working order for a little over a third of the cost of a mainboard and fitting.

Audiolab 8000A high end separates amplifier

5th August 2010
The plastic on the phono connectors had aged and broken, resulting in the sockets literally falling apart. They were removed and replaced with new ones, returning the amplifier to good working order.

Kenwood TK-3101 PMR radio

5th August 2010
This radio was being used as a communications system for a motorbike, however the radio was being kept underneath the seat which was restricting its range. The antenna was removed from the radio and a BNC connector fitted so that a good external antenna could be attached.

Roland SH-101 synthesizer

30th July 2010
The synth did not power on and had been in storage for some time in damp conditions. The reason the keyboard did not switch on was due to a blown internal power supply. The power was restored by replacing a power transistor. Poor connections on the line output and headphone sockets were re-soldered. A broken pitch bend control was repaired. Upon testing, it was discovered that a section of the keyboard was not working. This required the complete dismantling of the keyboard, upon which it was discovered that the printed circuit underneath had corroded due to the damp conditions and opened a common circuit line that served the top section of the keyboard. Damp had damaged a number of traces which had to be repaired. The keys were given a good clean as they had been removed and the synth was returned to good working order and excellent physical condition.

Korg MS2000R hardware synth

30th July 2010
The synth did not power on due to a broken power socket. The solder had failed and the pads lifted from the circuit board.

Pioneer CDJ1000 MK3

27th July 2010
The deck had a faulty pitch fader and the customer had purchased a new one and had it fitted by a phone shop. Unfortunately this phone shop did not know what they were doing and did a poor job of de-soldering and replacement of the fader and ended up blowing up the power supply. Tidying up the poor work and repair of the power supply brought the deck back to good working order.

Marshall Valvestate 100V guitar amplifier

13th July 2010
The amplifier was suffering from low volume and distortion. The cause was a failed solder joint on the power supply capacitors. The input jack was restored as it was intermittent and a missing foot replaced. The amplifier was restored to good working order.

Marantz PM-66SE separates amplifier

13th July 2010
The left channel was low in volume and noisy. While the fault did not show on the bench, it was noticed that many of the solder joints were on the way to failure. The joints were resoldered and the amplifier returned to good working order.

Pioneer AVH-P5700DVD in car DVD player system

7th July 2010
The low level signal inputs and output were clicking and picking up noise. This was because a small fuse, tucked away inside the radio had blown due to a small current flowing through the ground system of the low level input and outputs. If I were being cynical, this pointless fuse is to catch out people installing the sound system so Pioneer can charge extortionate amounts for repair and installation of the failed system. The stereo was modified to repair and prevent the problem from happening again. The stereo was returned to good working order.

Sennheiser EM2004 radio microphone

5th July 2010
The radio mic receiver base station required an investigation into its sensitivity as it appeared to perform poorly against another unit. The base station checked out OK, in fact its sensitivity was excellent. The problem was due to a weak transmitter on the radio mic caused by weak batteries. The microphones RF output power drops significantly, reducing its range when the battery is weak - even though visually it appears to work fine right down to near zero output.

Advent 7206 laptop

4th July 2010
Laptop would not power on, something was also rattling around inside. Upon inspection it was discovered that the rattle was a loose screw... bad news if that shorts anything out on the laptop mainboard! It possibly could have been causing the switch on issue and had moved when the laptop was transported. The screw was removed and the battery taken out and reinserted to cycle the PMU and the laptop started up without problem. A few checks later found no problems.

Nakamichi 630 tuner/preamplifier

4th July 2010
This nice professional FM tuner unit was dropping a channel intermittently. The cause was age of some edge connectors inside the unit. The daughterboard connections were cleaned thoroughly and each sprung contact formed and cleaned to make a better connection. It was noticed that the front panel indicators and illumination had burnt out, so the indicator bulbs were replaced too. Tarnish was removed from the phono connectors and where there was damage to the front panel such that light from the illumination leaked through, matching paint was applied. The tuner was returned to good working order.

Work for Modus Consulting

3rd July 2010
A small monitor was repaired due to a problem with its power adaptor. Some strange issues with explorer.exe on a PC were fixed. Wireless internet connection issues were resolved on several laptops and a desktop machine.

Sony PCG-Z1XMP laptop

3rd July 2010
Laptop was suffering from bluescreen issues - cause was old wireless drivers. Updated and problem disappeared.

Dell Inspiron 1545 laptop

1st July 2010
The laptop would not charge its battery despite being connected to power and was also overheating. The shift key had also come off and the underlying mechanism lost. The cause of not charging was particularly annoying - Dell have made the power adaptor 'intelligent' so if you plug any other adapter in apart from Dell's the laptop will refuse to charge. Of course, with this new feature comes the usual bugs we have come to expect with insufficient product testing - a show-stopping computer killing bug for absolutely no valid reason whatsoever. The bug was overcome, then the BIOS updated to permanently fix the problem. The shift key was repaired and the computer cleaned up. The laptop was returned to good working order. Update: Upon further testing prior to returning it to the customer it was discovered that the soldering to the power socket had failed AND the charger was intermittently faulty! Sometimes things are not what they seem.

IItronics 8Gb MP3 player

1st July 2010
The MP3 player would not connect to the computer when connected to a USB port. The cause was failure of the soldering on the USB socket. This was re-soldered and the player was returned to good working order.

Yaesu FT-23R 2m handheld transceiver

30th June 2010
The transceiver refused to TX, RX was ok. The cause was not PA failure, but increased internal resistance of the battery - the voltage dipped below the required level on TX and reset the internal computer. The battery was tidily split apart and re-celled with 2500mAh NiMH cells for excellent battery life and returned to good working order.

Kenwood TH-79E FM handheld dual band transceiver

29th June 2010
The display on this handheld transceiver was intermittent and flickery. The cause was a poor conductive rubber contact between the processor board and the lcd display unit. The transceiver was repaired and returned to good working order.

Mackie Fussion 3000 active speaker cabinet

23rd June 2010
The customer brought this in with the previous failed speaker. While no syptoms of failure were affecting the sound of the speaker, on inspection the PSU capacitors were failing. 12 were replaced refurbishing the unit back to good reliable condition.

Mackie Fussion 3000 active speaker cabinet

22nd June 2010
This huge active speaker were suffering from a buzz when it was hot after some time at high volume. The reason was failure of the PSU capacitors for the bass, mid and high amplifiers. They were swollen and significantly reduced in capacitance which was worsened when hot. 12 were replaced bringing the speaker back to working order.

Technics 1210 vinyl deck #2

18th June 2010
Deck did not switch on due to a power surge which killed the power supply. The power supply was repaired, the deck was cleaned up and the speed control lubricated so it was smooth again.

Technics 1210 vinyl deck #1

18th June 2010
Deck did not switch on due to a power surge which killed the power supply. The power supply was repaired, the deck was cleaned up and the speed control lubricated so it was smooth again.

Alesis RA-500 Reference studio amplifier

11th June 2010
The amplifier has been purchased as untested and had suffered some damage in the post. The speaker binding posts had also been damaged and snapped off! The amplifier also did not switch on. The supplied power lead had a 3A fuse which was insufficient for powering the amplifier. It was replaced with a 5A and the amplifier powered on without fault. The speaker binding posts were replaced, the chassis bent back into the right shape and the amplifier tested at 120W/ch RMS into 8 ohms for an hour without issue, getting nice and toasty in the process.

Pioneer CDJ-400 cd deck

10th June 2010
The deck did not switch on. The problem was initially traced to a faulty surge protector, however after testing for several hours the fault returned. On inspection, there was a short measured on the regulator board. The fault must have blown the surge protector previously then cleared itself.  Because of the design of the deck, to get at the board to faultfind and replace components the front of the deck had to be dismantled making the job hours longer than it should have taken. The fault was traced to a wire link carrying 12V that was folded over onto the groundplane of the board, shorting out the supply - a manufacturing defect. A thin layer of varnish had been preventing the short, however on a hot day and being used for several hours, the thermal expansion of the board had squeezed the layer of varnish and pierced it! The link was desoldered and replaced and the deck was returned to good working order. It is lucky that the fault showed on the test bench, as this is a type of fault that would cause headaches for both the customer and myself, as the fault would inevitably had cleared by the time the deck has cooled down and been returned to me, only to return when used in a hot enviroment!

Pioneer DJM-909 professional mixer

9th June 2010
The mixer has a broken channel 2 fader and also the fader shape controls at the front of the mixer were damaged and broken. The headphone socket was also loose. The fader was replaced, the fader shape controls repaired and the headphone socket fixed so that it will never loosen again. The mixer was returned to good working order.

Pioneer CDJ-400 cd deck

9th June 2010
The deck was intermittently freezing, which can easily ruin a mix. The deck was given a good check over and its internal software program was updated. This cleared the freezing problem and repaired the deck.

Numark Dimension 4 1.9kW amplifier

4th June 2010
The amplifier was brought in with the thermal cut-out circuit breaker faulty. The customer hoped that the cut-out was just the problem, however channel  B had failed catastrophically and the large overload current caused by this was tripping the breaker. The breaker had been reset so many times that it had burnt itself out. The customer decided that the repair cost was uneconomical (due to the number of transistors that would need replacing) and decided not to go ahead with the repair. The customer gave the broken amplifier to me for spares which I am grateful for, thank you Damon.

Professional Repair Services is 1 year old!

1st June 2010
Well time does go quickly! I would like to thank customers that chose to use us over the last year. Things started quite slowly and have gently accelerated over the following months, leading to the last two months which have been the busiest ever! New customers have come to us through the website which has climbed in popularity to the top result or very near the top result in a variety of Google searches for audio, CDJ and radio repairs in the Cardiff and South Wales area. Many customers return with additional equipment to repair. Repairs to amateur radio equipment have also been increasing too, with people from outside the area sending in their radios via courier.

Due to the increase in business, we are considering moving to some new premises in Cardiff in order to expand. We are also considering developing some interesting products for those of you out there that like to wield your own screwdrivers and save yourself some cash. Watch this space.

Our goal has always been to provide a service that makes it worthwhile to repair medium value electronic equipment and will remain so over the next year.

Advent 7206 laptop

20th May 2010
The laptop was freezing 3 times a day and on startup error boxes were displayed. The memory and hard disk tested ok. The processor cooler was cleaned and the computer was cleaned up and given a thorough check over. It was restored to good working order.

Behringer DJX700 mixer

19th May 2010
Soon after switch on, a nasty buzz came out of it and the signal meters showed maximum. This was due to a bad 7915 regulator shorting out the power supply. A replacement plus some new rectifier diodes solved the problem and brought the mixer back to working order.

Wilderness Radio Sierra QRP HF transceiver kit

18th May 2010
The radio had been built from a kit but the builder was having problems getting any RF output. The circuit board in the PA area had been damaged in an attempt to find the fault. The PA was stripped down and rebuilt and the circuit board cleaned up. A junction FET was replaced. Still no output, much to my disappointment. The full alignment procedure was carried out, bringing with it a healthy 2W output - the RF tx signal had been attenuated by poorly aligned band-pass filters.

Numark TT500 high torque vinyl deck

18th May 2010
The deck was brought in with the following problems. There was no start action, the platter had to be started by hand. The motor then took over, but ran at a slow speed. The cause was failure of an internal 3.3V supply rail - a replacement IC and resistor repaired the deck.

Pioneer DJM-600 mixer

17th May 2010
Oh dear, this mixer had apparently been lent to an all weekend scratch DJ party in Bristol. Needless to say, there was not much left of it afterwards! All faders had been destroyed and several knobs were missing. Despite the damage done, it was restored to good working order at a good price, much to the delight of the customer.

Stanton C324 CD deck

17th May 2010
Deck had been plugged into 240V when it was an American 120V version. Result was smoked PSU and input filter. Replacements repaired the deck.

Audiohead 1kW power amplifier

11th May 2010
Amplifier has a dead channel B after being connected to a shorted bass bin and run at high volume. The damage to the amplifier was catastrophic, all output transistors dead plus other components - over 20 in total. A strip down of the amplifier module, set of new output transistors, power resistors and diodes repaired the amplifier.

Allen & Heath Xone 92 professional mixer

9th May 2010
Faders 1, 2 and 3 were scratchy and the volume went to full when they were tapped. The faders were removed, dismantled and carefully reconditioned back to good working order, repairing the mixer and avoiding the ridiculous cost of replacement fader units. The fader units in this particular model are very high quality for a DJ mixer.

Yaesu FT-8800 2m/70cm FM transceiver

8th May 2010
The radio was suffering with no output on 2m. 70cm was ok. After tracing the 144Mhz carrier through the pre-amp stages it was determined that they were ok and the final output transistor was ok. Two diodes were discovered open in the output filter circuit, replacements from Yaesu fixed the radio.

Wharfedale SPV-15B bass bin

7th May 2010
The bin was suffering from distortion and also came with an amp with a totally blown channel. Upon examination of the insides, a piece of metal was found that was shorting out parts of the crossover, causing the distortion and shorting out any connected amplifier. This is what killed the 1kW amp that was driving it, ouch. Removal of the metal and replacing some missing jack nuts and screws brought the bin back to working order.

Jan AM CB radio

7th May 2010
TX audio was distorted due to bad solder joint. Re-soldering cured the problem.

President Andrew J AM CB radio

6th May 2010
The signal meter was stuck, causing the appearance that receive wasn't working. This fooled me for a while as I traced the mixer and IF stages. Removing the signal meter and loosening the needle bearing cured the S meter fault. Loss of TX was caused by a solder speck in the TX area. Very low modulation levels was due to a bad microphone.

Uniden 200 UK FM CB radio

6th May 2010
The only thing that lit up on this CB was the signal meter backlight. A shorted electrolytic capacitor in the 8V supply caused the loss of 8V and death of RX and TX. Changing the cap brought the radio back to working order.

Alberry M408 Monoblock high end amplifier

6th May 2010
Phono connection on rear was very loose and the wired connections had been severed from the amplifier board. The socket was removed, stripped, rewired, refitted and connected to top-side components so that the amplifier board need not be removed - which would otherwise been a lengthy job. The repair brought the unit back to good working order.

Alberry M408 Monoblock high end amplifier

6th May 2010
Phono connection on rear was intermittent. This was due to fatigued socket and poor solder on the pcb connections for the socket. The socket was repaired in a similar manner to the above.

Marantz PM151 amplifier

4th May 2010
Amplifier was bought in dead. The fuse had blown - a replacement bought the amplifier back to life but it ran very hot. This was because the bias had drifted up to about an amp, making the output transistors and heatsink very hot which itself caused a further bias current rise. This overheating leading to over-current condition had blown the fuse. The bias current was set to 60-80mA, repairing the amplifier.

Marantz PS2100 amplifier

4th May 2010
The amplifier has two problems, it was going into protect mode and the front motorised panel wasn't working properly. It was going into protect mode due to poor solder joints on the underside of the mainboard that feeds the amplifier modules. The panel didn't work properly due to a faulty switch that failed to tell the amplifier logic that the panel was closed. Both faults were repaired and the amplifer returned to good working order.

Radio Testimonials

1st May 2010
I have added a new section to the website 'Radio Testimonials' for the comments I receive from people who are pleased with the work carried out to their radios and the first is from Mr. David Bowen, who I repaired an FT-857 for.

Yaesu FT-857

Faults: Nasty internal crackle making transceiver unusable, DSP filtering issues.

Hello Dan,

My thanks go out to you. What a wonderful job you have done repairing my
857-D. Since I have had the radio its always been a tiny amount off
frequency on 2M SSB. I conducted a test with my brother earlier who
lives in Shropshire and he said it was bang smack on frequency.. Thanks
very much Dan.

Regards

David Bowen
2W0ZJA
Brecon

Thanks David for your comments on the repaired transceiver. I am very glad you are pleased with the work carried out on it. 73 and GD DX!

Icom R-71E

28th April 2010
Customer bought in a general coverage receiver with a complicated major fault and several time consuming age related problems related to capacitors. A list of issues was drawn up to create an accurate and detailed estimate of repair which took 3 hours. The work in total would have taken a full day of work on the bench and had already taken half. The customer decided that the radio was not worth repairing and offered to pay me for my time which I was grateful for, so I charged half rate for three hours of skilled faultfinding for a total of £45, which incidentally is the same as a single hour of diagnosis fee at another radio repair shop here in Wales. I also prepared a detailed list of the faulty components that required replacement. He then decided that this was too much and took the radio away without any payment at all. I offer a value for money, competitive, high quality, skilled repair service with excellent support and free initial examination on many items. However due to the complicated and time-consuming nature of amateur radio equipment repair and due to this incident there will now be an examination fee charged should the customer decide not to go ahead with the repair. CB equipment initial examination remains free.

For the record, I decided to check on Icom service charges which 'start at' £27.50 + VAT per half hour plus parts. That's £64.63 per hour compared to our £30 per hour, more than twice the price!

Yaesu FT-857 HF transceiver

23rd April 2010
The reported faults were a wide open receive and a nasty crackle affecting rx performance. The wide open receive was caused by incorrect DSP settings. The crackle was more difficult. After quite a long time trying to find the source of the crackle, it was traced to the AM 455kHz filter. A replacement cured the fault, returning the radio to good working order.

Technics 1210 record deck

20th April 2010
The tonearm was loose, the balance and tonearm mounting mechanism was removed and the tonearm fixing screws tightened.

Pioneer CDJ-500S cd deck

19th April 2010
Deck stopped reading CDs after about 15 minutes. The laser had failed, a replacement was fitted repairing the unit.

Realistic TRC-2005 CB transceiver

13th April 2010
The radio has been connected the wrong way around without an inline fuse. The protection diode shorted as a consequence and the high current flow that resulted burnt out a track on the pcb. The diode was replaced and the track repaired bringing the unit back to good working order. The FM deviation (modulation) was turned up too, as it was far too quiet.

Kenwood TS-440S HF transceiver

9th April 2010
This radio was suffering from gremlins in the PLL board and has really had me scratching my head for some time. Finally, in the last few days I have cracked it!
The radio was really off frequency and the only tuning steps were every 10kHz. This was due to twiddled bandpass filters in the PLL board, which supressed the wanted mixer products from MIX5 and instead the PLL locked to a different mixer product! This was why it was so far off frequency (653kHz) and did not tune finely since the fine tuning signal was lost. Some other minor problems were also fixed. Very happy about fixing this, it has been taunting me for ages.

Kenwood TS-440S HF transceiver

6th April 2010
Radio was suffering from unstable VCO-5 causing drifting frequency and unlock. Cause was poor solder joints in the VCO-5 area and the classic 'glue problem'. The glue was removed with solvent and picked away from the PCB, curing the problem.

Pioneer CDJ-500S cd deck

6th April 2010
Unit would not eject CDs after a period of time in storage, this was due to a sticky mechanism and slack drive-belt. Unit was repaired back to good working order.

Bose SoundDock iPod dock

31st March 2010
The dock had been used without the appropriate slot adaptor for the iPod used with the system. This led to the snapping of the plug completely off the dock. Luckily, the plug was undamaged. It was soldered back on and reinforced with epoxy resin to bring the unit back to good working order.

FT-707 HF Transceiver

30th March 2010
Dear me, what a mess. While the exterior looked ok apart from where it had been dropped at the rear, the insides were, in search of an alternative word, knackered. As I worked on this and tested it, more and more problems came out of the woodwork.
1. Some RF board stands were missing and where they were missing the board was screwed in until it almost touched the case. This also warped the board. Some replacements were filed to the correct size and put in.
2. Receive and transmit in CW and USB, LSB were off frequency. The display indicated the wrong frequency, something other than the required transmit freq. or actual! The VFO and SSB mixer stages had to be realigned. The display frequency was incorrect due to drifted counter master clock. This was realigned to get the right frequency displayed.
3. Mic/carrier knob all sticky and one turned the other. The knobs were removed, the shaft straightened and the knobs reattached with a small clearance.
4. VFO was wobbly when the unit was knocked. This was due to poor crimp joints in a plug thats connects to the RF board. On closer inspection another wire was unattached!
5. Random wires cut inside rig! - Oh dear. Black was VFO ground and was attached to the VFO chassis. Blue was a 10m band select line. A coaxial cable was left cut and tidied away, hopefully nothing important...
6. S-meter way out - realigned for S9 50uV and scaling similar to Kenwood TS-850.
7. Excessive output power - This baby was putting out over 140W! This was readjusted to give 110W output as specified in the service manual.
8. Clarifier control all wobbly and not centred. The clarifier switch was dirty, this was cleaned and the clarifier realigned so that centre was centre.
9. Tuning knob finger wheel all loose and wobbly. This was due to the knob being attached with an incorrect screw. A replacement was fitted so it didn't wobble and felt 'nice'.
10. More broken/snipped wires on AF and RF board - Urgh this time a crystal oscillator select line. The plug that was giving trouble before had another invisibly broken cable too.
11. Marker tone oscillator was in the wrong place. This was realigned so that zero beat was exactly on the external reference oscillator.
12. More bad connections on RF board causing intermittent TX. This time it was several tracks around plugs that had been repaired before by someone, but not properly.
13. Low output on 10m. This was a puzzle for quite some time, since there was nothing written about this in the service manual. There is a control for output power on one band only, this is VR06 on the IF board. This was set to give 100W on 10m, finally!
14. Starting to get quite annoyed now. The RF bandpass filters had been twiddled! Gah, thankfully only a few had been turned and their correct settings were determined. 40m was incorrect, 12m incorrect, 10m incorrect.
15. The counter was 'wobbly' in the top half of the 10m band, reading low. This was due to poor solder joints on the counter board.
16. The 12m 38.9875Mhz crystals and 10m[D] 43.9875Mhz crystals were missing as reported by the customer. Some replacements were sourced and fitted. On fitting it was discovered that the AF board around all the crystal oscillators was heavily damaged from a too hot soldering iron.
17. And on to the original reported problem... Sometimes RX would not return when switching back from TX. After some detective work I noticed that the audio dropped out as well as the CW RX offset, giving me at last somewhere to look on the circuit diagram. There was a relay on the AVR circuit board that was hidden inside the rig so it was almost inaccessible. Luckily I could just get it open with a screwdriver and squirt some cleaning fluid inside it with a straw. And it was fixed :)
 
Finally, this rig was back in working order.
 

Hard Disk Data Recovery Samsung 500Gb

18th March 2010
Drive had been dropped and continued to be used, then stopped working. Contained vital documents, photos etc. When drive was connected to a PC, the power supply tripped indicating a short on the drive electronics somewhere, which was traced to the 3.3V supply line. A transient suppression diode across the supply line was removed, the short disappeared and the diode measured short. When reconnected to the PC the drive span up as normal and all data was recovered. The failure was not related to the drop at all - probably the PSU with the external drive killed the diode.

Yaesu FT-840 HF Transceiver

18th March 2010
The radio arrived with the fault 'no display'. Upon testing it was determined that there was no display, no backlight, no CPU operation and hence dead RX. The fault was caused by a shorted electrolytic capacitor, which caused a power resistor to overheat and go high in value. This starved the internal 5V supply of voltage and also caused the resistor to heat enough such that it almost desoldered itself. A replacement capacitor and power resistor brought the radio back to good working order.

Crashing PC for business customer

15th March 2010
The computer was freezing every now and then and displaying an error on startup. The problem was traced to a buggy version of the Blackberry software, which was upgraded to the latest version. Hopefully this will have cured the problem, but it could also be hardware related so time will tell for this machine.

M-Audio BX8a Active Studio Monitors

11th March 2010
The speakers had been turned up too loud for too long. One speaker had blown a tweeter. The tweeter was removed and inspected after picking off all the glue holding it together. The coil had opened near to where the lead was attached so some careful heating to remove the enamel and some solder closed the circuit, bringing the unit back to good working order. Note to users of active monitors - they're for studio usage at moderate volumes not all night high volume party usage!

Peavy Messenger Pro Sub active subwoofer

10th March 2010
The amplifier had blown, causing the mains fuse to blow. Customer fitted another fuse which blew again. The amplifiers in these subs are switching Class-D (or class-T) amplifiers, making them more tricky to service. A pair of MOSFETs had blown, taking out some surface mount components and unfortunately the output of the driver IC, rendering the unit useless. A replacement amplifier unit from Peavey costs more than a replacement sub! The repair was abandoned.

IT services for Modus Consulting

26th February 2010
I haven't documented any of the IT services provided to companies in the news section, but will do so from now on. Setup of print server, general maintenance and cleanup to restore speed to PCs, RAM upgrades and workstation preparation for new employees were completed today. A broken windows install was repaired so that networking functions worked properly and an emergency safety backup of company data was made due to warnings signs of possible disk failure in a vital file server. The warning events turned out to be spurious during investigation after the data had been backed up as quickly as possible - any signs of disk failure are not to be taken lightly!

Allen and Heath Xone 42 mixer

25th February 2010
This mixer had liquid spilled into it at a party. The mixer was immediately turned off and left to dry out - a good decision by the owner. Upon switch on, only half the lights came on and there was no sound. Upon dismantling the mixer, the power and sound backplane was discovered to have corrosion and leaching damage which was cleaned up and repaired. The power supply was checked and was ok. Power was still missing so a further investigation of the pcb tracks with a multimeter showed an open track and 'via' that did not appear visibly damaged. Repairing the track brought the mixer back to life.

Samsung 913N LCD monitor

24th February 2010
The monitor displayed 'Not optimum mode' and refused to display a picture even if the right mode was selected. This was due to a failed controller chip. A mod was done in an attempt to bring it back to life which partially worked - but after some time on heat build up in the case and the associated increase in temperature of the chip cause the fault to return. Some heat-sinking was attached to the chip which seems to have cured the fault. Update: IC causing problem still a bit wonky, programmed replacement IC unavailable and replacement cost greater than value of monitor. Repair abandoned.

Philips 1200 series laptop

19th February 2010
Internet Explorer was acting up and laptop was slow. Cause was a trojan horse and spyware.

Advent 5301 laptop

19th February 2010
Laptop was overheating and was unstable. Cause was dust build-up in cooling assembly.

Fender Twin Reverb valve guitar amplifier

17th February 2010
Well this was interesting, a really old valve guitar amplifier - late sixties early seventies vintage. Very poor physical condition and electrical condition, broken reverb, very low distorted output. The low and distorted output was cured with a set of replacement output valves and the dead reverb was caused by a fried output transformer that drives the reverb tank. The secondary had shorted and led to the failure of the primary high impedance winding. The transformer had to be shipped from America and thankfully repaired the amplifier to good working order - very loud and really nice sounding reverb.

Boss ME-50 guitar effects pedal unit

16th February 2010
The power jack was intermittent as well as the headphones jack. Somewhat annoyingly to repair them meant having to dismantle the entire unit to get at them. The fault in both was not the socket or the soldering, but failure of the PCB tracks around the solder. The effects unit was restored to good working order.

Denon DN-S5000 CD deck

10th February 2010
The deck had a faulty pitch control which had gone non-linear due to a spilled drink. The control was removed, dismantled, thoroughly cleaned and lubricated. This returned the deck to good working order.

Apple Powerbook G4 Aluminium laptop

27th January 2010
So many problems, don't believe the Apple hype :(
1. Stuck battery, release mechanism broken. 2. Power adaptor jack worn out and cable split and shorting. 3. Power socket intermittent and broken. 4. Battery worn out. 5. Laptop hinge loose. 6. Broken screen clasp. 7. Damage from dropping.
Started by repairing the power jack which was obviously shorting by the sparks coming off it when the cable was flexed. Repaired the plug nicely by dismantling and resoldering with some unbroken flex and fixing with resin. Then discovered that the power socket was broken too. To dismantle the laptop the battery needs to be removed which was stuck. Took about 2 hours of gentle levering and playing with the release control to free it. Finally got cover off laptop, discovered that everything needs to be dismantled to get at the board with the power socket on. Everything! Removed motherboard, hard disk, cdrom, speakers, pcmcia slot mechanism. Removed power board, removed socket and installed heavy duty power socket. Snipped off nicely repaired power jack plug and put on a standard power plug and fixed insides with resin. Repaired battery release mechanism. Reinstalled pcmcia socket, speakers, motherboard with new thermal compound, cdrom and hard disk. Dismantled screen to investigate loose hinge, which was really quite frustrating to do. Repaired screen latch. Discovered that the loose screws were not easily accessible without dismantling the screen itself further, which I decided against due to the possibility of damage to the screen. Why design like this? Absolute madness! Reassembled screen cursing Apple and reassembled laptop. Booted first time ... excellent! However when shutting down or sleeping the laptop refused to turn back on. A power management unit reset allowed the laptop to switch back on, but the problem remained. Installed power management unit update from Apple, problem remained. Started cycling the knackered battery in an attempt to recover some capacity and 'work' the PMU. Finally, sleep and shutdown started to work properly, turns out the knackered battery prevents switch on by presenting an unexpected voltage to the PMU. Battery update allows deeper cycling of battery, so actually getting a reasonable amount of on time from the old battery and thankfully working sleep and shutdown modes.
So the laptop was returned to good working order, at last.

Dual core home, office and media PC build

15th January 2010
A computer for the home, office and media with a build price of £500 was specified by the customer. Two DVDRW drives were essential, a monitor was not required, gaming not important and the computer must be upgradeable in the future. Due to upgrade path and price point the AM3 socket with DDR3 memory was selected. The computer was built into a smart PC case and had a attractive, low-power reliable wireless keyboard and mouse. The computer spec was an AMD Phenom II X2 545 processor (dual core 3Ghz), 4Gb PC3-10666 DDR3 RAM, 1Tb Samsung F1 high speed hard disk, Radeon HD 2400 Graphics with VGA, DVI and HDMI output for HD televisions, High speed wireless N network card, 52 in 1 card reader and a high reliability Gigabyte motherboard with solid capacitors, two PCI-Ex ports for future expansion with graphics cards and two free memory slots for future expansion. The PC effortlessly played hi-def content due to the Radeon HD 2400 chipset and remarkably played Half Life 2: Episode One at high graphics settings at a very smooth framerate. That's really quite impressive given the integrated graphics chipset and miles ahead of the competition in this area. Also, the processor is actually a quad core chip with two cores disabled! These can be unlocked! Pictures are available here, scroll down to the bottom of the page, it is the second build described.

Marshall Lead 50W valve amplifier

14th January 2010
A respected valve amplifier using two EL34 valves. Problems were a faulty pre-amp valve and capacitor causing distortion well before peak output. The components were replaced, broken knobs repaired, scuffed case repaired and everything given a good clean, returning the unit to good condition and working order.

Pioneer DJM600 mixer

12th January 2010
Missed an entry! The mixer was brought in due to losing 2 channels. This was due to a damaged connecting cable which was repaired. The headphone socket was also loose, so this was tightened and some mis-located LEDs on the front panel put back in the right place.

Pioneer CDJ800 deck

7th January 2010
Deck was skipping and not reading CDs properly. Mains transformer was also buzzing fairly loudly and Cue and Play buttons failed. The laser was OK, a good clean fixed the reading problems and a check to the mains transformer showed that it hadn't failed and was not overheating. The Cue, Play and reverse search switches were replaced and the deck returned to good working order. Update: Despite the deck behaving OK on the bench, the deck was returned as it was intermittently not reading disks. A replacement laser was fitted for parts cost only, curing the problem.

Pioneer CDJ200 deck

6th January 2010
The Cue and Play buttons on the deck had completely failed, with no tactile action left at all. Replacement switches repaired the unit.

Pioneer DJM400 mixer

6th January 2010
The headphone socket had stripped its threads and disappeared inside the mixer. Repair to the socket body and a new nut and washer fixed the mixer.

Quad core high performance PC build 'BEAST'

20th December 2009
A computer for gaming and high performance computing was specified by a customer with a target price of £800. A component list was drawn up and each component researched and chosen considering maximum performance for price with features important for future upgrades. The final spec was 22in widescreen monitor, quad-core Phenom II X4 925 processor, 8Gib of PC10666 DDR3 RAM, 1Tb Samsung F1 HD, Gigabyte ATI Radeon 4870 1Gb graphics card with Zalman cooler, DVDRW and smart, understated Cooler Master Elite 334 case. This is truly a performance beast which chewed through any game I threw at it with silky smoothness at ultra-high graphics settings and zipped though Windows 7 x64 like it was a light snack. Pictures are available here, scroll down to the bottom of the page, it is the first build described.

Samsung VM6000 laptop

17th December 2009
Really old school laptop - 256Mb RAM 400Mhz Celeron 6.4Gb HD and 800x600 screen. Well how much was wrong with this? Dead power adaptor. Faulty keyboard. Dead battery. Hopelessly underpowered. Changed power supply, repaired keyboard, replaced NiMH battery cells and installed linux. So now it is at least usable, still hopelessly slow though.

Toshiba Tecra 8200 laptop

14th December 2009
Unbearably slow XP install and Control Panel and a few other things had been disabled. Computer took ages to boot and ages to open internet explorer. The computer was riddled with viruses and spyware. It was cleaned up, brought up to date and back to working order.

Technics SV-V2 amplifier

8th December 2009
Audio was distorted and channels were intermittent. Due to the age of the amplifier the switches and pots had oxidised. Dismantling the unit to get access at the switches and pots and cleaning and reconditioning the relevant components returned the unit to good working order.

Alesis RA300 and Samson Servo-170

8th December 2009
These two amplifiers were reported to have failed channels. A quick test showed that both amplifiers were working on both channels. The amplifiers were subjected to a rigorous test into an 8 ohm dummy load for an extended period at near maximum rated output power. Neither showed any signs of failure and so were given a clean bill of health and returned to the customer. Perhaps a failed cable or shorted speaker cable was causing the problem.

Old Hammond electronic organ

7th December 2009
This was an interesting piece of equipment! A discrete synthesiser with several processor boards, VCOs, sound generation boards and amplifiers. There were two problems reported, the first being that the Leslie tremolo speaker system was not working and that the arpeggiator wasn't working problem. The loss of sound was due to a failed speaker which was replaced. The arpeggiator problem was not a failure, the synth has a large variety of switches, some that look like indicators only but are actually switches as well, one was engaged when it shouldn't have been.

Logitech Speaker System

1st December 2009
Wire to connect remote control to PC was broken. A replacement cable and 3.5mm jack cured the problem.

Wireless internet problem

30th November 2009
Solved a wireless internet problem due to mis-configuration of router and poor quality wireless cards in the client machines.

Fujitsu-Siemens Amilo laptop

27th November 2009
Laptop would not switch on or charge. The power adaptor was faulty a replacement fixed the problem. The laptop was checked for viruses and spyware, some spyware was removed.

File and e-mail server

19th November 2009
Moved a file and e-mail server for Modus Consulting.

Packard Bell MV-51 laptop

11th November 2009
The laptop would not charge. It was discovered that if the power jack was flexed in a particular direction the laptop would charge and switch on, indicating a failure of either the socket or the soldering of the socket. To get at the socket required the entire laptop to be dismantled, everything! A barely visible hairline crack was discovered in the soldering of the socket - this was repaired and the laptop assembled. The CPU and GPU heat sink compound was found to be too thick and very rubbery - this was replaced with a much more heat conductive alternative and resulted in a much better cooling fan response to heat. The laptop was returned in excellent condition and good working order.

Samsung M40+ laptop

10th November 2009
Wireless internet problems and extreme slowness were the problems with this laptop. A detailed clean up and optimisation of the system resulted in a much improved system response and quick startup. The wireless internet issue was repaired and the laptop returned to the customer in excellent working order.

Sony VAIO PCG-Z1 laptop

9th November 2009
The laptop was slow, several errors occurred on startup, wireless ethernet was not working and neither was the Vodafone mobile internet adapter supplied with it.  A full clean up, removal of corrupted files and troubleshooting driver installation file permissions problems fixed the startup problems and internet access issues and the mobile internet adaptor installed cleanly with the repaired system. The laptop is much more responsive and nice to use, and according to the customer problems were fixed that Sony support could not. The work was done overnight since the customer was leaving for an important business trip and needed the laptop repaired immediately.

Icom 706 transceiver

4th November 2009
More rotary encoder tuning dial problems. Reconditioning of the encoder repaired it, but it may need a replacement in the future. Customer is local so doesn't mind returning it should it need a replacement. Update: Encoder started to fail a week later, so a replacement was fitted for parts cost only.

Numark CDN90 dual CD player

3rd November 2009
Unit came in with deck B unreliable when seeking to a track. Further investigation of the unit uncovered a marginal laser on deck A, a near dead one on deck B and damage to the ribbon cable leading to the laser assembly on deck B. Both decks were replaced - numark spares are relatively cheap - and the ribbon cable repaired. The unit was returned to good working order.

Hitachi 80Gb Laptop HD Data Recovery

23rd October 2009
The drive had been declared dead and unrecoverable by a shop on City Road and the customer decided to see if we could recover the data. Sure enough on first examination it was dead, didn't spin up, not recognised in BIOS. Using precautions against dust, which can ruin a drive, the fault was determined to be that the drive had been dropped and the drive heads has crashed onto the disk surface and jammed the platter assembly inside. The heads were unstuck and moved away from the disk surface into the parking zone, allowing the drive to spin up as normal. Over 90% of the data was recovered from the disk with all important files recovered.

Pioneer CDJ1000 CD deck

15th October 2009
Deck came in with the symptoms: no main display, no button operation, no loading motor operation and the centre display all lit up. Reason for failure was the loss of the +5V supply to the main microcontroller and DSP processors. The power supply was repaired with some replacement components and the deck restored to good working order.

Lenovo J110 PC

8th October 2009
Computer was totally dead, no bios, no beeps nothing. The hard disk was also missing. Visual inspection of the custom motherboard showed 8 dead capacitors, all swollen. Replacement of the capacitors and a new HD brought it back to life. A legitimate install of Windows XP Pro OEM and up to date drivers brought it back to good working order and a custom recovery DVD was made to replace the missing one that was not supplied with the computer. This is a common practice by computer manufacturers which trips up end users when things go wrong and then they ask for £50 for the rescue disks. This repair job is a good example of our capability to recover machines that would otherwise be thrown in the bin.

Mackie 32.8 studio mixing desk

1st October 2009
This is one beast of a mixing desk from Long Row Studios. The desk had several problems, faulty output channel, dead Mix-B output channel and a scratchy pot. The customer also wanted the direct outs modified so that they were pre-fader, pre-eq, post-insert outputs. This was accomplished by working out the circuit of the input jacks, cutting tracks, installing wire-jumps and breaking the circuit in some ribbon cable for each of the 32 channels. The faulty output channel was due to dry joints, and the dead Mix-B channel was due to a dead audio chip. The unit was restored to good working order.

HP Compaq DX2400 Micro-tower

29th September 2009
Computer crashed and restarted during boot up. Culprit was an incompatible or corrupted system service. Computer was cleaned up and restored to good working order.

IT maintenance for Modus Consulting

29th September 2009
We are pleased to announce that Modus Consulting based in Cardiff have chosen us to provide IT build, maintenance, repair and networking services.

Electrolux vacuum cleaner

28th September 2009
Well we don't normally repair things like vacuum cleaners, but anything electrical we can do. The fuse had gone and the power switch had moved inside its housing so it never switched on.

Pioneer DJM-600 mixer

24th September 2009
Headphone jack body had come off, stripped its threads and the nut had worked its way into the master output circuitry and hooked itself around some components. The jack also had blu tack inside it stopping it from working properly. The jack was replaced restoring the mixer to good working order.

Pioneer CDJ-800MK2 CD deck

15th September 2009
Unit had been dropped, breaking the disc retention mechanism. Also, the loading arm bearing was worn causing unreliable load/unload of CD. Every now and then the CD would jam inside the player with a nasty clicking sound. The retention mechanism was repaired and the loading arm wear was repaired returning the unit to working order.

Pioneer CDJ-800 CD deck

8th September 2009
PSU failure caused deck not to take CDs and report error E9101. Some troubleshooting and repair fixed the unit.

Stanton C314 CD deck

27th August 2009
The CD mechanism micro-controller chip died, not the motor driver as I had first thought. This meant a horribly expensive new board which returned the unit to working order. The deck was also converted to 240V UK mains.

Stanton C324 CD deck

26th August 2009
Unit was a 120V model which had been plugged into 240V mains for long enough to cook the mains transformer and some filter components. Replacements brought unit back to working order, luckily the regulator circuitry was hardy enough to withstand double the input voltage and stop the rest of the electronics from being destroyed.

Pioneer CDJ100s

24th August 2009
Internals had jammed due to dust - cleaning out and re-lube restored it to working order.

Denon AVR1906 home cinema amplifier

18th August 2009
Unit went into protect mode immediately after switch on. Faulty connections in the protect circuitry was the problem, fixed and returned unit to working order.

Wharfedale T2811WS 28in TV

3rd August 2009
TV did not turn on, nice burning smell coming from back. A 2kV 2.2nF capacitor had failed, a replacement fixed the set.

Microphones, stands and mixer amplifier available for hire

28th July 2009
We now have a set of three 600 ohm low impedance microphones for hire along with three quality microphone stands. Also available is an 8 channel mixer amplifier suitable for band use in small venues. It has a powerful main output as well as monitor outputs plus 8 channels for microphones, guitars and other instruments.

Hitachi L42VP01U 42in LCD TV

13th July 2009
Set did not turn on. Reason was failure of the internal PSU - failure of the power factor correction circuit and failure of the standby PSU with several fried surface mount components, chips and power components. Replacements and some further troubleshooting brought the TV back to working order.

Kenwood TS-850SAT HF transceiver

5th July 2009
Varying power output on different bands was caused by band-pass filter selection failure. Several corroded tracks were the problem, these were jumped and radio was returned to working order.

Icom IC-210 2m FM transceiver

4th July 2009
Customer wanted CTCSS fitted to this old transceiver to access repeaters - installed cstech unit with jumpers to select the tone frequency, replaced backlighting bulbs and fixed an intermittent audio fault.

Security alarm system

2nd July 2009
Customer brought in main circuit board which he had identified was faulty to see if it could be repaired. A shorted rectifier diode blew the mains fuse. The rectifier was replaced and the board was restored to working order.

Prosound 200 amplifier

1st July 2009
Amplifier would not switch on. Faulty power switch - dismantled, repaired and restored to original working condition.

Doh! Email problems!

30th June 2009
It was brought to my attention that the email above was not working and that emails were being bounced. Sure enough, they were! I am not sure how long this has been occurring for so if you have been trying to get in touch via email, please accept my apologies and try again. I unfortunately was the problem by not configuring my email client properly.

Kenwood TR-7625 2m FM transceiver

27th June 2009
TX power dropped off fairly rapidly in this transceiver. Cause was overheating driver and resultant poor solder joints developed over time. Some replacement components and additional heat-sinking brought it back to working order.

Yaesu FT-290R transceiver

22nd June 2009
This radio was in a fairly sorry state - off frequency by a significant amount, distorted SSB tx, CALL button for 1750Hz tone generation not working, no backlight. Was restored to good working condition by realignment of PLL, replacement of final and duff diode, removal of failed mod to CALL button and replacement of backlight.

Kenwood TS-780 transceiver

18th June 2009
Transceiver was 2.5kHz off frequency. Realignment of carrier generation board and IF board cured the problem.

Nikkai 600W 12V dc to 240V ac inverter

16th June 2009
On switch on, unit tried to start up but tripped with fault indication. A pair of mosfets for generating the AC waveform had died, replacements fixed the unit.

Skytec 8 channel powered mixer/eq/amplifier

15th June 2009
Looks like a handy piece of equipment - 8 channel mixer with effects, eq and high power amplifier all built into a rugged case for lugging around with bands. Same as the Phonic version. Unfortunately, the amplifier had fried in a spectacular fashion - 10 new transistors, a few resistors and a couple of diodes later and it was restored to good working order.

Repair of iPod speaker dock

4th June 2009
Terrible construction led to the failure of the soldering of the surface mount socket that plugged into the iPod. Was repaired, but could not reliably stand up to repeated use so the repair was abandoned and a workaround was implemented of using a charging dock attached over the top of the unit to feed audio into the speaker system. Since it could not be repaired to its original condition, there was no charge however the customer gave £10 for the time spent working on it - thank you Anthony.

Repair of Kenwood PS-430 power supply

3rd June 2009
Was giving out unregulated 23V instead of 13.8V, not healthy for any connected radio! This was a frustrating puzzle, as the pass transistors and regulator were all ok - turned out to be a tiny ceramic capacitor that had failed and turned into a resistor of about 6k. This allowed enough current to flow to fully switch on the transistors allowing a nasty 23V through. Replaced the capacitor, plus a few dried out electrolytic capacitors and a leaky transistor returning the unit to good working order.

Repair of Icom 706 transceiver

28th May 2009
Seized tuning dial due to seized rotary encoder shaft and bearing. Restored to good working order.

Repair of Marantz PM-30SE separates amplifier

28th May 2009
Fault in bias circuit caused overcurrent condition and tripped protect, eventually getting so bad it blew the fuse. Fixed fault and returned amplifier to working condition.

Sound systems and equipment hire available

21st May 2009
We are happy to announce that our sound systems are available for hire. The range is from a small announcement system suitable for public events and children's birthday parties to large systems with up to 8 huge bass bins for heavy duty dance events. See the hire page for details.

Repair of CDJ800

20th May 2009
Laser mechanism gummed up and really dirty. Careful clean and lube returned unit to good working order.

Repair of Music M8 wooden hi-fi

15th May 2009
On/off volume switch and potentiometer completely ruined. Rebuild of potentiometer and replacement of switch returned to good working order.

Repair of TASCAM X-9 mixer

1st May 2009
Faulty left channel on PGM2. Faulty sockets on rear. Scratchy action on cross-fader. Repaired sockets, input stage and reconditioned cross-fader to return to good working order.

Repair of CDJ800 tabletop CD deck

29th April 2009
Faulty laser unit. Replacement restored unit to good working order.

Repair of CDJ100s

23rd April 2009
Faulty rotary encoder and fascia switches. Replacement of each repaired the unit to good working order.

Professional Repair Services website up and running

4th May 2009
We are pleased to announce that the website for PRS Ltd is up and running. Simple design for compatibility with all browsers and we hope it gives a clear impression of what type of business we are running.