Macintosh Performa 550

izverycool

New Member
May 21, 2019
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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.

Mike
 

Dale Mahalko

New Member
Jul 25, 2019
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Just to make sure you are doing this correctly, as it is not mentioned...

Googling indicates there is a master power switch on the back that should always be turned on.

To power up the computer, you need a good battery on the motherboard.

Then press the "Arrow" key on the keyboard, usually the top-right corner of a Mac keyboard, also used as the Eject key on the newer iMacs.
 

izverycool

New Member
May 21, 2019
11
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I think I'm going to check the motherboard and analog board to see if it fits the criteria of the capacitor juice David mentioned in his Macintosh LCII restoration video, I have a LCII myself and it has that plague on it too. That machine shows a white/gray screen and does nothing else at all. (At least the power supply works). When I got the LCII, I didn't realize how bad the plague was until a second look after David's video came out. I don't feel like getting it out right now to check (the Performa 550). Once I do, I'm probably going to outsource the work since I'm not skilled at all in soldering / desoldering (never learned how) along with my Sega Game Gear which needs capacitors replaced (no backlight). I saw a website called MacCaps Repair Service that I might go with and send all the boards and game console I need repaired.
 
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