Diagnosing and Repairing a Faulty Commodore 64

In the latest video from the Triple Freedom channel, a Commodore 64 was having unusual issues, initially showing a black screen on startup. After ruling out common issues like a broken PLA, the focus shifted to the VIC-II chip. Testing with an oscilloscope revealed that the clock signal for the CPU wasn’t functioning, which raised concerns about a possible CPU failure. However, upon checking the VIC’s pins, it appeared the chip itself was faulty, leading to its replacement. Despite this, the system remained partially functional, showing random screen artifacts. Further diagnostics suggested a RAM issue, which was confirmed after testing the U27 RAM chip. Replacing the faulty chip restores the C64 to full operation.