When Triple Freedom set out to test an old Commodore 64, the system appeared lifeless. The computer showed nothing but a blank screen, and its keyboard was already damaged. But with patience and a bit of troubleshooting, the team soon discovered that this machine still had life in it.
Inside the case, they found a ROM switcher attached to a small expansion board. Removing the original ROM and placing it directly back onto the motherboard made all the difference. Using cartridges and diagnostic dongles, they confirmed the machine could boot again.
The real challenge surfaced when they tested the sound. A faulty SID chip was to blame, causing both audio issues and unexpected interference with control ports. To prove it, they swapped the faulty SID back in after installing a working one with a heatsink. The difference was striking: the defective chip produced errors during diagnostics, even implicating unrelated components like the U28 chip. With the working SID in place, the Commodore 64 passed its tests and produced clean sound.
This part of the repair was a success, but the computer’s keyboard remains unusable. While the system can run software and produce audio again, it will need more work before it is fully restored. Triple Freedom made it clear that keyboard repairs are planned for a follow-up video.
What makes this repair especially engaging is the clear demonstration of how a single bad SID chip can affect multiple areas of the system. Viewers see firsthand how diagnostics can be misleading when faulty chips cause errors that appear unrelated.
The project highlights how much functionality can be saved with careful testing and parts replacement. Though the keyboard issue lingers, the Commodore 64 SID chip repair shows real progress, and the next update promises even more.
