VIC-20 Repair / Transplant Surgery - December 8th 2013

Mark Vergeer's picture


A little while ago I got a second VIC-20 which was in a cosmetically almost mint condition. Sadly the motherboard has a fault where it fails to read the joystick and the keyboard correctly resulting in the controls in games not functioning. The VIC-20 I had works great but cosmetically has seen better days. The label has come off and there has been extensive yellowing of its case. One has a serial number only in the ten thousands while the other machine has a serial number well into the hundred thousand. The cosmetically good looking machine being the oldest of the two and the yellowed machine being the younger system. So the younger system works great but looks sh*t and the oldest system looks great but runs sh*t.

The idea was to make both systems function 100% and take a look at their guts to see if they were any different. Well they are. The sizes of the motherboards are vastly different, the younger machine having a much smaller motherboard. Similar size differences can also be seen in C64 motherboards from later revisions. The new system had almost all its chips soldered to the motherboard whereas the old system had most of its chips socketed. The latter is much more easy to service. Simple swapping out the chips was a no go so I decided to do something else. Check out the video to see what I did and how I fared. Mind you I am not an electrical engineer and nor do I claim to be an expert.

This video is a bit of a test using two camera angles with two cameras recording simultaneously. I use a smaller cam to shoot some photos and some close ups of the systems. The pacing in this video is slow. It's just me doing the work - waffling along with you guys tagging along.