Macintosh Performa 550


New Member
May 21, 2019
I have a couple of early 1990's Macintosh Performa / LC all-in-one computers that do not power on whatsoever.

I opened up the case on one of the machines to look for a leaking battery or bulging capacitors, but nothing seems to be out of place. I replaced the clock battery for a new one, tried a variety of ADB keyboards, tried resetting the PRAM, but the machine refuses to power on.

Any idea of what the problem could be? Could these early 1990's Macintosh computers have analog board problems like the 1980's Compact Macs?

If anyone could shed some light, I'd appreciate it.