TRS-80 Model 100 Capacitor Replacement
Added 2024-06-25 20:12:55 +0000 UTCHello!
This was a spontaneous project that worked out well and quickly in between other projects. I've been meaning to repair this Model 100 for years now and had never got around to it. I had ordered parts for it along with caps for repairing an IBM 5154, well the IBM ended up needing another round of parts so while that order was shipping I figured I could take a crack at this.
This ended up not being totally perfect at the end but I'm still pretty happy with the results overall and I'm looking forword to trying it out some more now.
Video Link: https://youtu.be/p3TPviBEVy0
Comments
I cleaned the capacitor leaks in possibly not the best way, I used 91% isopropyl. I've heard vinegar is better at neutralizing the corrosion but I haven't tried it myself. I have had a lot of luck using CLR for battery leakage so it might be viable as well, I haven't encountered that much trace corrosion in the office and haven't brought that there yet to test with. It's difficult to say what the best method is since you have to test it on something that has failed and then you don't know the leak damage is "stopped". It might still be going on my Model 100 but it might take years for anything noticeable to happen. My rough rule of thumb is to try to find where the traces go, measure resistance between the points to make sure it's still low (5ohms would be a lot). If it is, clean it and move on. If it's not or visually it just doesn't seem right, I'll clean it more aggressively after removing the solder mask over the trace. Then I'll tin it with solder. If I'm not happy after that I'll bridge it with a wire. Depending on what you are doing, the wire bridging might be "free" by bending over a part leg and I'll just do it for security, my next video will have an example of that.
Tech Tangents
2024-06-27 13:38:27 +0000 UTCVery fortuitous as I have a Model 100 that needs a recap. Did you clean up the capacitor leakage before putting new caps in? How did you do that and what did you use? If you didn't, what were your reasons. Cheers, Doug
Doug Merrett
2024-06-26 23:52:24 +0000 UTC
