ghfeil@white.toronto.edu (Georg Feil) (09/11/90)
After 7 years of service, my C64 died last saturday. I'm wondering if anyone
has seen the following symptoms, so I might have a clue what's wrong:
In its last moments of life, the machine started randomly accessing the
early portions of screen memory, and the foreground colors were alternating
rapidly. There were most likely other affected memory areas, but these were
obviously not visible. After about 5 seconds of this, the machine crashed.
I cycled the power, and it rebooted (made it to startup screen) but the
foreground colors were still going wild. It crashed again almost immediately.
Future attempts to restart were not successful (screen stayed black).
At first I suspected the power supply, since it had died before. However the
voltages check out.
Any ideas out there?
Thanks,
Georg.
--
Georg Feil Internet: ghfeil@white.toronto.edu
-or- : georg@sgl.ists.ca
..if all else fails, try:
{uunet,pyramid,watmath,utzoo}!utcsri!white!ghfeil (UUCP)
ghfeil%white.toronto.edu@relay.cs.net (ARPA)reynolds@felix.UUCP (David Lee Reynolds) (09/13/90)
In article <1990Sep10.144605.16326@jarvis.csri.toronto.edu> ghfeil@white.toronto.edu (Georg Feil) writes: >In its last moments of life, the machine started randomly accessing the >early portions of screen memory, and the foreground colors were alternating >rapidly. There were most likely other affected memory areas, but these were >obviously not visible. After about 5 seconds of this, the machine crashed. >I cycled the power, and it rebooted (made it to startup screen) but the >foreground colors were still going wild. It crashed again almost immediately. >Future attempts to restart were not successful (screen stayed black). > >Any ideas out there? In the past I worked as a repair rep for a local Commodore repair depot. If I were the one to work on this unit the first thing I would try is the PLA (Programable Logic Array). This one chip controls ALL memory and display accesses. The odds are great that this is the culprit. I would go as far to say that out of every 10 C-64's I fixed 9 had this chip bad. They can be purchased from many sources for about $10 to $15 bucks. If you need a source just email me. If you have a friend with a C-64, you might want to swap these parts first, (the PLA's are almost always socketed), to verify that it will fix it! >Thanks, >Georg. >-- Good Luck! David Lee Reynolds (legs,spsd,zardoz,hplabs)!felix!reynolds