I have a Macintosh Colour Classic in my collection, a beautiful yet flawed machine, which has given me a lot of grief over the years. I sent the main logic-board and analogue board over to Charles AKA Uniserver (who used to run maccaps.com - site seems to no longer exist, but here’s an archive.org mirror) and he replaced a bunch of capacitors that were the most likely failure points. It worked for a time after that, until it didn’t. I tried diagnosing it, I noticed there was a part wedged between two transformers making a nasty chirping/squeaking noise. I replaced that, and still the same issue of it not turning on. I left it for a year or so, and when a friend (Hi, Alex!) mentioned he was taking some machines up Canberra to someone who specialised in old-school Mac repair, I got in touch with him. With that person’s help, I managed to narrow down the root cause. Seems somewhat obvious in hindsight, but the issue was with another component that helped with feeding power to the squeaking component… Now, bear in mind it was cunningly hidden underneath an RF shield, so I couldn’t see the poor blacken husk of the failed component! Anyway, once I removed that and soldered in suitable replacement, it sprung to life! First run was outside on my driveway using a long power lead - I didn’t trust it not to explode :P
Currently listening: Asthenic - “Phase Change II”