C64 Pictorial Fault Guide. The Pictorial C64 Fault Guide 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 fault guide suggested that this fault could be caused by a faulty 7406 (U8) or 2 other 74LS14s - because I have the parts & wishfully thinking these may be relabelled on the 64c I replaced U23 (74LS14) & U22 (7406) - my tester showed both as being faulty but the issue persists.
The Pictorial C64 Fault Guide Hardware Retro Computing from retrocomputingforum.com
Description 'Out of sync' screen instead of normal startup Changing VR2 made no difference, but the 2200 uF capacitor at C19 measured zero capacitance.
The Pictorial C64 Fault Guide Hardware Retro Computing
The pictorial fault guide suggested that this fault could be caused by a faulty 7406 (U8) or 2 other 74LS14s - because I have the parts & wishfully thinking these may be relabelled on the 64c I replaced U23 (74LS14) & U22 (7406) - my tester showed both as being faulty but the issue persists. Changing VR2 made no difference, but the 2200 uF capacitor at C19 measured zero capacitance. The test will start automatically and cycle through each of the checks
The Pictorial C64 Fault Guide. Here's some handy resources to get you started with C64 repair: The Pictorial C64 Fault Guide is here: https://www. The output voltage from the regulator VR2 was measured and found too low
The Pictorial C64 Fault Guide. 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 A picture-oriented diagnostic guide for Commodore 64 computers