I have a McIntosh MC30 with a bad transformer that's partially replaced. The MC30 is a mono power amplifier from the 1950s. This has been in pieces for years.
I have a second MC30 with a fault I haven't even started troubleshooting. It makes a nasty hum when I turn it on. I don't know.
But my third MC30 works! I just need to get back to two good ones.