Repair a SONY DSC-P93 that has stuttering OVF zoom and an error message
Although not regular flooded type, AGM batteries can also be restored by adding water if it's not too far gone.
I built a NAS with a cursed motherboard and TrueNAS Scale
I restored a Sharp GF-777, replacing all belts and friction wheels, and the pinch roller
A very high gain (80db or x10000) differential AC signal amplifier
Repairing a pair of classic Alesis monitor speakers 维修一对经典的Alesis监听音箱
A Roland XP-80 synthesizer repair writeup
A 3x AA battery powered phantom power supply design