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help mac lcII wont start

If the PRAM battery is dead, the little CPU it keeps running will go bonkers. (Yes, PRAM is inside a tiny CPU on this board)...

Replace the battery.

If it still won't work, leave the battery in it and take a small flathead screwdriver and run it down each side of the chip, shorting the pins together as you go. Then it should power up.

Sounds screwy but I've done that to dozens and dozens of those old machines back when I worked at a repair shop in the mid 90s.

RJ
 
OK... near the middle of the board is a small tubular crystal. It's connected to the chip right next to it, labeled UD8 EGRET (If I'm reading the silk screen correctly)...

That chip has a Motorola and an Apple copyright on it and is a surface mount chip. That's the one you want to rub the screwdriver across the legs on. Just put it at the top of the legs, where the legs meet the body of the chip and slide it down the tops of those legs, making contact with the legs as you go.

Sounds silly as hell, but I've done it many many times. Some Mac boards had a button on the motherboard you could use to reset the PRAM, but this one didn't. Too bad I didn't think about tracing that button circuitry back all those years ago.

If you still get the sad mac after that, post what the message is.

RJ
 
You either have a bad motherboard, VRAM SIMM, or bad RAM... At this point those motherboards are so cheap it's not worth doing component level repairs. We wouldn't do anything beyond swapping the SCSI controller on those boards back in the 90s because they were so cheap even then.

There's also a way to connect to the MAC boards remotely for diagnostics using the serial ports but I've never done it.

RJ
 
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