iz8dwf | C64 repair. MOS-8701, DRAM and a black screen. @iz8dwf | Uploaded September 2016 | Updated October 2024, 1 hour ago.
Commodore 64 serial n. UKB1 313653 repair. This is the very same C64 that my family bought in 1984. It was stored for about 20 years.
It's a rather brutal cut & paste of some hours of troubleshooting, sorry but it would take too much time to learn to do better videos for now :)
This unit had three unrelated faults.
1) MOS-8701 (crystal oscillator/generator) dead.
2) Ram address multiplexer dead (black screen).
3) One faulty DRAM chip causing "out of memory" error, and
stubborn enough to resist the usual piggybacking method for identifying the bad ram chip.
I prefer a long troubleshooting process that avoids de-soldering good chips.
Commodore 64 serial n. UKB1 313653 repair. This is the very same C64 that my family bought in 1984. It was stored for about 20 years.
It's a rather brutal cut & paste of some hours of troubleshooting, sorry but it would take too much time to learn to do better videos for now :)
This unit had three unrelated faults.
1) MOS-8701 (crystal oscillator/generator) dead.
2) Ram address multiplexer dead (black screen).
3) One faulty DRAM chip causing "out of memory" error, and
stubborn enough to resist the usual piggybacking method for identifying the bad ram chip.
I prefer a long troubleshooting process that avoids de-soldering good chips.
