Looking for help troubleshooting a black-screen 64C Shortboard?
What I know:
5V is good
Reset is OK
1MHz Clock Good
800mA Idle Current (No Loads/Externals)
RAM Chips are at approx 38C
(Oddly 4Degree diff between them)
SID Removal Yields Nothing Better
One common game cartridge fills black screen with a non-sensical character. Interesting enough in good stable positions. Only a single cartridge yields this result. Seems telling NOT VIC?
CS on Kernal/BASIC ROM is pulsed active/busy on scope during on/idle-time.
Only noticeable warmth is from VIC, 8500, and SID.
Anyone uncomfortable with the 2 RAM chips running a 4 degrees different from one another?
Thanks in advance. If this is best moved to a private group chat, I would be happy to do so.
I have socketed the following chips:
8500
VIC
RAMs
ROMs
Clock Gen 8701
Have not yet swapped with known good chips since all my other C64 machines are much older revs.