I have an SE/30 and it's developed a worrying fault.
When I turn it on from cold, it seems to start OK, but if I turn it on while "warm", it will sometimes make an arcing, crackling noise, which is quite disturbing.
The noise seems to be coming from around the power switch. I've stripped the system and I can't see any signs of obvious damage. I thought the problem may have been the power switch itself as it felt a bit "crunchy" so I stripped everything down and added some Deoxit, which made the switch a lot smoother, but I still seem to be getting "zort" noises on warm start.
When it "zorts", the system seems unstable too (The boot screen is scrambled like the system has crashed. so while you can see what it was trying to draw, it's overlayed with checkerboard garbage. I can't get a photo as I immediately turn it off if it does this.) so further into the power supply?
Not sure what to check next. Open to suggestions. I'd guess it must be the power supply unit? I'll strip it further next weekend and see if I can see any more places the problem could be. I've visually inspected all the PSU capacitors and they all look fine.
This high voltage stuff is a bit more scary than the stuff I usually work with so I'm not afraid to say it's a bit "brown trousers" time for me.
Cheers and TIA.