C64 Pictorial Fault Guide. The Pictorial C64 Fault Guide Via Hacker News, a probably quite useful visual gallery of failure modes of the Commodore 64: c54-u5_5 800×599 57.5 KB Be sure and match up any faults with what you are observing using the pictorial fault guide.
The Pictorial C64 Fault Guide from www.pictorial64.com
Below is the image from guide that I recognized as my fault The Pictorial C64 Fault Guide General tips - ROM (U3 - U5) It's not particularly common for the ROM chips on a C64 to fail, but it does happen occasionally
The Pictorial C64 Fault Guide
Changing VR2 made no difference, but the 2200 uF capacitor at C19 measured zero capacitance. The C64 is a great machine to start getting into repairing because it is incredibly well documented and there's a lot of great sources to get information from for it these days Failed 74LS629 Oscillator Chip Desoldered from Position U31 on a Commodore 64 Circuit Board
The Pictorial C64 Fault Guide. Description 'Out of sync' screen instead of normal startup Task: Explore the Commodore 64 Pictorial Fault Guide for Troubleshooting a Computer with Problems Needed: Web Browser Time: 10-15 minutes Introduction The best place to start when diagnosing a Commodore 64 that boots to a black or garbled screen is the Pictorial Fault Guide
The Pictorial C64 Fault Guide. The definitive pictorial diagnostic guide for Commodore 64 computers The test will start automatically and cycle through each of the checks