My trusty Lombard G3 recently experienced some unexplained fits:
- it froze repeatedly one day, each time requiring a hard restart, but working fine for several hours inbetween each freeze
- But in the early evening it froze again and then wouldn't restart. The hard restart at first got me to the lighted screen, but no little mac icon ever appeared. To get it to restart again I had to unplug it and remove the battery, but that got me only a 'click' from the speakers--the screen remained dark, the harddrive didn't spin up.
- I had experienced something like this several months ago, when the computer would get to various points in the start-up process (lighted screen w/ icon, wallpaper and MacOS9 icon) but then freeze. I solved this problem by removing the RAM I had installed as an upgrade a couple years ago. So I did the same thing again--removing one simm, then another, and finally both of them--but still just a 'click' and a dark screen at restart.
- Despairing of fixing the problem, I went to bed, leaving the poor G3 with its battery and RAM out, so that it could think overnight about what it had done. Or not done, as the case may be.
- This morning, after putting in the least-suspect RAM simm, the G3 started right up, going through its disk repair process and then loading its extensions. When it got to the desktop it gave me a 'System Error: "Finder" / Error type 41" message then froze again. But a hard restart got it working just fine, apparently.

So what are likely problems here that I can work on to prevent another big crash?

Thanks for any advice....

Most likely your processor is going bad. If you are experiencing frequent crashes, that usually is the culprit. Also if you get any errors at startup such as "...has detected a problem with the built-in cache memory" , then that is another sign it is the processor, but you don't have to have both symptoms...

Processor replacements are available from the link below:

http://www.powerbookmedic.com/xcart1/cu ... hp?cat=340

-Bradley
PowerbookMedic.com