RCM - RETRO COMPUTER MUSEUM

GENERAL => HARDWARE/SYSTEMS DISCUSSION => Topic started by: MrTrev on January 19, 2018, 05:27:39 PM

Title: C64 Fault finding help, doesn't conform to usual issues
Post by: MrTrev on January 19, 2018, 05:27:39 PM
HI everyone, I've searched through the forum and Google, I can't seem to find anything similar to my faulty C64. So, Lemon 64 users, you're my only hope Wink

It's a black screen, so I dropped in a PLAnkton, thinking it might be a PLA issue, but that didn't cure it, the internal bridge rectifier was oscillating so I changed that, measured all the voltages and they are fine. All PSU's are fine and giving correct voltages. So I plugged in my dead test cart, still a blank screen, but SID was singing away nicely. Plugged in the datasette and pressed rewind, switched it back on and the rewind worked for about 5 seconds, then nothing. So I'm thinking it's possibly a bad Kernal rom? Unfortunately for me, only one CIA, the SID, VIC-II and PLA are socketed, and check out fine, so I could do with any suggestions before I socket and replace any other chips.