Normal startup except corrupt/flickering character graphics. The machine was still operating, but as it warmed up, more and more flickering appeared on the screen, until it finally crashed. Cooling the VIC-II chip with cold spray lessened the flickering, but swapping in another VIC-II chip did not fix the symptoms. Swapping in a new Character ROM also did not help. Replacing the U26 logic chip finally did the trick. First screenshot taken from the startup screen, second one is from a diagnostic program.
Contributed by SamW @ forum64.de
Bad U26 (Logic)
