Jun 102010

I’ve had a pair of Macintosh Classic II computers awaiting diagnosis and repair for over a year now. Both suffer from the same issue – a checkerboard pattern on the screen that appears on startup and remains. After perusing the helpful forums over at the 68k Macintosh Liberation Army I determined the issue is almost certainly leaking capacitors.

Not long ago I was able to purchase a replacement Classic II logic board for a few dollars on ebay as an unused Apple Service part. I was thrilled that I might get at least one of the Classic II Macs back to health without having to remove and replace a bunch of capacitors with a soldering iron.

Above is a photo of the new and the old logic boards. It’s pretty easy to tell which is which. Sadly, though, the new logic board is not without problems. Although the Classic II now starts up properly there is no sound. I’ve reseated RAM and ROM modules without any change. Another tour through the 68KMLA forums reveals this is a common symptom of, you guessed it – leaking capacitors.