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Commodore 64C Restoration - Part 1
February 12, 2026
A few years ago I acquired a few pieces of Commodore equipment which had been stored for a few decades in a barn. I had hoped to revive as many of these as possible to save them from the scrap heap but it seemed like there was always another project that got in the way. This year I decided to make some of the Commodore equipment a priority, and what follows is a multi-part series outlining the restoration of a Commodore 64C, the first piece in the collection. Unfortunately I seem to be missing some of the pictures and video I took of this whole process, but I'll add in what I can salvage.
The computer was going to take some work. The case had been opened at some point so the shell pieces, keyboard and shields were just piled together in a heap. Despite that, the system did power on though the C-64 Diagnostics showed some issues. Also the chroma in the image would fade in and out although I didn't know if that was an issue with the computer, or something in my AV setup as I was having to use some dodgy cables, and my composite to HDMI convertor wasn't liking the signal.
There was dirt and even some straw littering the PCB and case.
A few keycaps and springs were missing, luckily the posts were there.
Diagnostics showed issues with the Keyboard, Control Port and SID
The first step was to get everything cleaned up. Not only was it pretty gross to have on the bench, but perhaps the grime was hiding corrosion or other issues I couldn't see. A few of the ICs were socketed, and I went about removing them with the idea being that it would give the sockets a chance to get cleaned, and it may also limit stress on the removed chips. In total I was able to remove the CPU, VIC-II, MOS8701 clock generator and the SID. Once those were off the board I prepped the ultrasonic cleaner using a 1:15 mixture of Simple Green Crystal in water heated to around 40C and put the board through a couple of cycles lasting a few minutes, after which I did another cycle with some plain deionized water. The board was then thoroughly dried by shaking off excess water, followed by compressed air, then a low temperature soak in a toaster oven, followed by 48 hours of further drying at room temperature. I followed up once more with compressed air just to ensure there was no water remaining.
The top of the RF modulator and the RF shield were very rusty. Rather than trying to remove the rust from the RF shield I decided it made more sense to toss it. There was also rust stains on the bottom shell from the shield. I tried various combinations of rust removers and cleaners to try and get these out but in the end, it was a light sanding that was needed with fine grit sandpaper. I followed that with an ultrasonic cleaning of all of the shell pieces.
With the PCB and shell cleaned, it was time to tackle the keyboard. I don't have a keycap removal tool but I found that the Xbox360 X-Clamp removal tool worked well as it has a space to fit either side of a post, as well as a slight bend to help with levering. With the keycaps and springs removed I was able to run those through the ultrasonic cleaner and begin the drying process. The plastic frame was then separated from the keyboard PCB allowing this to also be washed.
The plungers that sit in the frame have carbon pads on them and I had heard that one of the best ways to clean them up and remove any 'sheen' that may have developed over time, was just to gently run them over a standard piece of paper, which has just enough friction to remove some of the surface without being too agressive.
The PCB for the keyboard was quite clean, so a bit of a dusting and some gentle cleaning on the carbon pads was all that was needed.
With the keyboard cleaned up, and the keycaps and springs now drying, I decided to see what I could do about the keys which had missing keycaps and springs. In total I was missing the left arrow from the top right corner as well as the 1, B, and M keys. I started first by measuring the springs which were 10mm OD x 15mm length x 0.5mm wire diameter. I couldn't seem to find an exact match but I did find some on Amazon which were 10mm OD x 15mm length x 0.6mm diameter so I ordered them up.
Once I placed these into the keyboard it became apparent that the feel of these springs was too different. the 0.6 gauge wire made the keys feel too heavy. I tried moving the replacement springs to the function keys thinking that at least there would be consistency in the main keys for lighter touch typing, but decided that it still wasn't a good solution. I dug around on AliExpress and I could not find an exact match for the springs but I did find some which were 10mm OD x 15mm length x 0.4mm, so I placed an order. Once they arrived I tried them out and they felt much better. Indistinguishable from the original springs, but I decided to ground them in the function keys anyway to provide the best experience.
The next thing was to deal with the missing keycaps. Initially I wondered about 3D printing some replacements. I searched around and found a few projects that looked like they could be promising including:
Commodore 64 - C64 key caps (CBM Stem) by pixelmaker04
Commodore 64 replacement key by yangsong
But then I found a project that talked about how each row of the Commodore 64C keyboard actually has keys that are a slightly different shape, and so it's not a one size fits all.
Commodore 64 Replacement Blank Key Caps by pixelmaker04 has multiple models for each row of the keyboard as well as models for the different size keys.
With this in hand I printed off some samples of the missing keys. The models are great by my available filament, and printer capabilities left a lot of be desired. The keys would require finishing work, and then I would also need to find a way to label the keys in a manner that looked decent. With these challenges in mind I decided to see what other options existed.
I scoured all of the typical online sources like eBay, but couldn't find a source that allowed me to get the keys I needed (left arrow, 1, B, M) in the right style and at a decent price. Eventually I came across Retroleum.uk which had a great setup for selling replacement keycaps. I had to select a few different qualities to match up with what they had available, but I was quite happy with what arrived. This certainly beat out trying to 3D print replacements and deal with the challenges of marking them.
So we've reached the end of this part of the project. The pieces have been cleaned, and the missing keyboard parts replaced. Next it's on to tackling the video issues in Part 2 - Chroma Coaster
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