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Repaired and serviced a NAD 3020 integrated amp.Fault reported / work requested:-Lost volume.Checked general operation O...
19/06/2026

Repaired and serviced a NAD 3020 integrated amp.

Fault reported / work requested:-
Lost volume.

Checked general operation OK before proceeding - coonfirmed the fault reported.
Removed the top and bottom covers for access.
Visual inspection for disstressed/degrading components, solder joints, loose wiring , fuses, etc.
Fault traced to the slow start/fast off circuit - replaced 3x capacitors, 1x resistor and 1x diode. Unit now giving audio as per normal operation with 15 second delayed start.
Also replaced all 4x 2,200uF main power filter capacitors with 2x 4,700uF/35V; replaced 2x other critical capacitors which commonly fail.
Checked all DC voltages OK.
Checked midpoint and quiescent OK.
Checked operation of all inputs and outputs OK.
Checked output voltage, symmetry and channel balance OK.
Refitted covers for final test.

Repaired a Yamaha 400S portable PA speaker.Fault noted:-Noise from bass driver and sometimes stops working altogether.Id...
19/06/2026

Repaired a Yamaha 400S portable PA speaker.

Fault noted:-
Noise from bass driver and sometimes stops working altogether.

Identified the issue as a broken tinsel wire at the bass driver - replaced with new. Checked operation OK.
Reassembled unit (completely stripped apart by the customer, there was no need to do that!).
Applied audio from the bench amplifier, concluded operation OK.

Repaired a second Audiolab 8000P stereo power amplifier.Faults reported/work requested:- Suspect stuck in protect mode, ...
18/06/2026

Repaired a second Audiolab 8000P stereo power amplifier.

Faults reported/work requested:-
Suspect stuck in protect mode, input connector block needs replacing (ground cap missing from the right channel input connector).

Removed the top and bottom covers for inspection/repairs.
Visual inspection for distressed/degrading components, solder joints, etc. OK. Checked DC voltages - noted imbalance in the DC main power voltages, one of the large power filter capacitors has failed showing high AC ripple. Released the PCB from the chassis and released the front panel asssembly for access, replaced all 4 of the power filter capacitors with new Rubycon 10,000uF/100V. Also replaced the broken input connector block with new. Reassembled for test. Powered up with DBT current limiting in place - normal load indicated, DC voltages now all present and correct. Switched to full wall power for continued testing.
Checked midpoint voltages and quiescent current OK.
Connected an audio source and loudspeakers, checked output voltage, symmetry and channel balance OK.
Concluded all audio and function tests OK, refitted the covers.

Repaired an Audiolab 8000P stereo power amplifier.Faults reported/work requested:- Only working on one channel, input co...
18/06/2026

Repaired an Audiolab 8000P stereo power amplifier.

Faults reported/work requested:-
Only working on one channel, input connector block needs replacing.

Removed the top and bottom covers for inspection/repairs.
Visual inspection for distressed/degrading components, solder joints, etc. OK. Checked DC voltages all present and correct.
Confirmed the fault reported. Located and replaced a shorted 2SC2911 transistor.
Rechecked DC voltages. Checked midpoint voltages and quiescent current OK.
Connected an audio source and loudspeakers, checked output voltage, symmetry and channel balance OK.
Released the PCB from the chassis for access, replaced the broken input connector block with new. Reassembled for test.
Concluded all audio and function tests OK, refitted the covers.

Repaired an Audiolab 8000C stereo pre-amplifier.Faults reported/work requested:- Noisy controls.Removed the top and bott...
17/06/2026

Repaired an Audiolab 8000C stereo pre-amplifier.

Faults reported/work requested:-
Noisy controls.

Removed the top and bottom covers for inspection/repairs.
Visual inspection for distressed/degrading components, solder joints, etc. OK. Checked DC voltages all present and correct.
Confirmed the fault reported. Removed the front panel; removed the Noble 204Y30KX2 potentiometer (volume) from the PC (access is from the bottom), Cleaned deoxidised the resistive elements with Caig Deoxit; reinstalled and reassembled the front panel for test.
Cleaned/deoxidised other control potentiometers and switches.
Connected an audio source and loudspeakers, checked all inputs and outputs OK.
Checked output voltage, symmetry and channel balance OK.
Concluded all audio and function tests OK, refitted the covers.

Checked and tested a Denon DN-A100 integrated amp.
17/06/2026

Checked and tested a Denon DN-A100 integrated amp.

Repaired and serviced a Laney LC15R guitar amp.Fault reported:-Issue with gain control.Confirmed much noise and intermit...
17/06/2026

Repaired and serviced a Laney LC15R guitar amp.

Fault reported:-
Issue with gain control.

Confirmed much noise and intermittent response.
Extracted the amp chassis for inspection.
Visual inspection and cold tests for distressed/degrading components, solder joints etc. OK.
Electrically tested all valves OK.
Checked DC voltages all present and correct, bias good.
Checked function of all pots and switches, pots noisy to various degrees, cleaned/deoxidised satisfactorily. Found the High input socket to be the main issue with intermittency - removed the PCB, replaced the jack with new; reinstalled the board for continued testing.
Checked loop, DI, reverb and footswitching all operating OK except reverb disfunctional due to an open circuit transducer at the tank output.
Checked output voltage and symmetry OK (30V p-p into an 8Ω reactive load = 14.1W RMS).
Rechecked and reset bias after a good warm-up period.
Concluded audio and function checks and tests OK, reassembled.

Repaired and serviced an Orange TH30 guitar amp.Fault reported/work requested:-General service and health check, didn't ...
16/06/2026

Repaired and serviced an Orange TH30 guitar amp.

Fault reported/work requested:-
General service and health check, didn't sound good last time gigged. Fitted spare JJ output tubes and tried again.

Removed rear cover and extracted the amp chassis for inspection.
Electrically tested all valves OK, including the set of Russian military 6Π14P/EL84 which was removed.
Visual inspection for distressed/degrading components, solder joints, etc. Noted all 4x grid stopper resistors burned and output not reaching full potential (20W max).
Checked DC and bias voltages all present and correct except V7 screen grid (effectively one valve shut down). LOcated and replaced open circuit 47R/5W screen grid resistor. Also replaced the 4x grid stoppers with new 2k2/½W resistors and both grid coupling capacitors with new 0.1μF/400V film caps.
Checked all pots and jacks functioning correctly.
Checked footswitching and loop working OK.
Checked output voltage and symmetry OK (full power 4 valves into a 16Ω resistive load - 62.5V p-p = 30.5W RMS; checked half power and 2 valve settings OK).
Concluded audio and function checks and tests OK.
Reassembled for final test with own speaker.

Repaired a pair of JBL Decade 16 loudspeakers.Faults reported/work requested:- Lack of top end on one speaker, could be ...
15/06/2026

Repaired a pair of JBL Decade 16 loudspeakers.

Faults reported/work requested:-
Lack of top end on one speaker, could be the L-Pad treble level control.

Confirmed the issue reported, definitely some intermittency with the L-Pad. Removed the bass drivers for access, cleaned the L-Pad rheostats with Caig Deoxit. Operation now OK.

Repaired a Marantz 2220 receiver.Faults reported/work requested:- Noisy/intermittent controls, service.Removed the top a...
15/06/2026

Repaired a Marantz 2220 receiver.

Faults reported/work requested:-
Noisy/intermittent controls, service.

Removed the top and bottom covers for inspection/repairs.
Visual inspection for distressed/degrading components, solder joints, etc. OK.
Checked DC voltages all present and correct. Checked midpoint voltages and bias current OK.
Connected an audio source and loudspeakers, confirmed the issues reported.
Cleaned/deoxidised all control potentiometers and switches, satisfactorily. Checked all inputs and outputs OK.
Checked output voltage, symmetry and channel balance OK.
Concluded all audio and function tests OK, reassembled for continued testing with the JBL loudspeakers.

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22 Fore Street, Barripper
Camborne
TR140QR

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