Repairs
This category covers real repairs, usually broken units bought cheaply on eBay or picked up as a return, with the fault unknown at the start. The point is the diagnosis: tracing a fault back to a specific component using a scope, a multimeter, and schematic knowledge, rather than jumping straight to a part swap.
Expect amplifiers, audio equipment, and general household electronics with genuine faults, not staged teardown content. Where a repair doesn’t succeed, that’s shown too. Not every unit comes back from the dead, and the process of finding that out is still useful.
SDG #368 Tricky Repair: Cambridge Audio Bluetone 100 - No Bluetooth
Diagnosing a Bluetone 100 that plays analogue audio but won't pair. Scope traces, EEPROM dumps and a CSR8645 to CSR8675 module swap that finally works.
SDG #363 eBay NAD Direct Digital Amplifier D 7050 Repair - Lots of issues
Repairing a faulty eBay NAD D 7050 digital amplifier: cracked SMPS transformer, dead caps, blown OLED boost converter and a burnt out white LED.
SDG #356 Repair of an Amazon Return Shinco Dehumidifier SDL5-10D
A faulty Shinco SDL5-10D dehumidifier bought for £5 as a customer return, diagnosed and fixed: blown display driver IC and an open-circuit resistor.
SDG #355 eBay Fosi Audio N3 Portable Bluetooth Headphone Amplifier Repair
A £4 faulty Fosi Audio N3 Bluetooth headphone amp gets a dead-channel diagnosis, ripped 3.5mm jack replacement, wire mod and LED fix, plus a listening test.
SDG #353 eBay Cambridge Audio DacMagic Plus Repair - High pitched whining noise from output
Diagnosing the DacMagic Plus high pitched whine: the real culprit is C179 on the DC-DC input, not C148. Full ESR testing and repair walkthrough.
SDG #351 eBay NAD Hybrid Digital Amplifier D 3020 V1 Repair - Won't power on (Hypex UCD102 Class D)
Fixing a no-power NAD D 3020 hybrid digital amp: open current sense resistors, shorted Class D MOSFETs and glue-corroded vias on the Hypex board.
SDG #282 Fixing the JBC Solder Feeder
The JBC solder feeder jammed constantly with 0.5mm wire. A softer spring plus a custom PTFE ferrule finally makes it feed reliably. Here's the fix.
SDG #259 Metallised Paper Capacitors still causing damage... Bosch GEX 150 Turbo
Metallised paper capacitors strike again. Teardown and repair of a Bosch GEX 150 Turbo sander, showing why these X2 caps fail and how to replace them safely.
SDG #258 Roberts RD70 FM and DAB Radio Repair - Faulty Volume Control
Fixing a Roberts RD70 FM/DAB radio with a faulty volume control. Teardown, Frontier Radio SoC, audio stage analysis and the actual repair.
SDG #240 Repair and analysis of a Varilight V-Pro AC LED Dimmer Module
Inside a failed Varilight V-Pro AC LED dimmer: fault finding, triac and MCU analysis, plus what the circuit design reveals about reliability.
SDG #202 4.5 Digit multimeter which keeps browning out
Troubleshooting a bench multimeter that resets and browns out under load. Fault finding on the power supply rail, plus what the repair reveals about build…
SDG #200 The repeated failure of Knightsbridge strip lights.
A teardown of repeatedly failing Knightsbridge LED strip lights, digging into the driver design, thermal stress and why replacements die too.
SDG #091 The Importance of Good EMC Design - Texecom Alarm System
A Texecom alarm system injecting conducted noise onto mains wiring shows why EMC design matters. Fault-finding, filtering and practical lessons explained.
SDG #033 Service Your Security Alarm Batteries!
A dead alarm battery killed the panel PSU. Fitting an Elmdene G13801N and why SLA batteries need servicing before they take the supply with them.
SDG #027 Symmetricom GPSDO 10MHz Reference Part 4
Replacing failed tantalum capacitors on a Symmetricom GPSDO GPS board with Panasonic POSCAP polymer parts, plus why old tantalums explode.
SDG #025 Cambridge Audio A4 Amplifier Modifications
Refurbishing a Cambridge Audio A4 integrated amplifier: full teardown, Panasonic and Rubycon recap, plus a front panel ambient LED mod.
SDG #022 Teardown & Repair of Acoustic Solutions SP101 Hi-Fi Amplifier - Error U52 U53
Teardown and repair of an Acoustic Solutions SP101 hi-fi amplifier showing U52/U53 error codes, plus a front panel rotary encoder replacement.
SDG #021 Samsung 46" TV Repair
Fixing a dead Samsung 46-inch LCD TV by tracking down a failed standby supply capacitor with an ESR meter, then replacing it with a Panasonic FM.
SDG #018 Benq LCD Monitor Repair Follow-Up
Follow-up on a BenQ/LG TFT monitor repair: a failed electrolytic on the control board plus a dry solder joint were the real culprits. Full diagnosis and fix.
SDG #017 Benq LCD Monitor Teardown and Repair
Diagnosing a BenQ LCD monitor that kept blowing 5A mains fuses. Full teardown, PSU fault finding and repair using scope, ESR meter and multimeter.