capacitors – classicmacs.org

Color Classic fix-a-thon

compact macs, hardware, repairs 2 Responses »

Jun 112010

3 Color Classics - front

My wife is thrilled when I turn the dining room table into a computer repair workshop. As you can see from the photos above the patients for this day included two Macintosh Color Classics that refused to start up. The Color Classic web server was temporarily taken offline to serve as my “known working” device to test parts from the other two.

One of the two nonworking CC’s was purchased for a song from ebay with a known faulty logic board but everything else was promised to be fine. This proved to be true – installing an LC575 logic board into it produced a healthy startup chime and a clear bright screen when booted from the internal hard drive . Since the system file on the HDD hasn’t been hacked it produced a bus error when trying to load the Finder, but that appears to be a software issue rather than a hardware one.

3 Color Classics - reverse

The second CC is one that previously worked fine and even has a rare Sonnet Presto Plus accelerator card installed. After sliding out the logic board and removing the accelerator card I could see very evident traces of leaking capacitors. I’ve located a working replacement logic board but it’s just a matter of time before it also succumbs to the ravages of time and suffers the same fate, so I guess I will need to brush up on my soldering skills.

Color Classic logic board and Sonnet Presto Plus

Sonnet Presto Plus accelerator and Color Classic logic board

The Color Classic web server is back online and I am still working on getting a spare backup ready to go to pinch hit in case of hardware failure. It is, after all, 17 years old. Back in 1993, when the Color Classic was released, Apple’s annual sales amounted to just under $8B, virtually all of it from sales of 3.3M Macs. In 2009 Apple’s annual sales were $36.5B, from 10.4M Macs, 54M iPods, and 20M iPhones.

Classic II progress

compact macs, hardware, repairs No Responses »

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.