I've quite a bit of experience with electrical repair (cars, home) and computers (replacing RAM slots type thing). I've repaired a fair amount of guitar amps, but mostly its just replacing switches and potentiometers, or fixing bad solder joints. I am comfortable with a soldering iron and hot air rework gun, and a family friend has a mountain of old diagnostic equipment (worked for the schoolboard, so oscilloscopes, frequency generators, variable power supplies, etc.).