I’m looking to either buy a new one, or repair my current one. I started developing an intermittent problem a few months ago - any time you touched it, it would jump to the highest pitch in its range (behaving like a switch instead of a variable resistor). Sometimes it would behave normally. There was no apparent correlation. Just being temperamental!
Eventually, of course, the intermittent problem became a permanent problem.
I have open it up and explored a bit. There are no apparent breaks, and I re-metled the three solder connections in case one of them was “cold” - no luck.
What I DID notice though, is that I could flex the ribbon’s PC board a bit and make it work - obviously a short somewhere - a bad trace on the board? The resistance strip shorting somehow? I can’t tell, and no test I have tried gives me any indication.
It could be cracked or broken element. Rare, but happens.
Usually the symptom you’ve described is from a short due to a missing insulating washing or a solder connection (from the wires to it) shorting against the mod panel.
If the element does indeed have a crack at one end, you may be able to use silver paint to repair it.
I still stock the covering tape, but sold all 25+ complete ribbon assemblies I had.
I might still have a spare resistive element though.
By element, do you mean the silver strip under the touchpad? I have taken it completely off. I can hold it in place with finger pressure, then use my other finger and press it. Again it just jumps to the top-most pitch unless I flex the board, then it behaves properly.
Is the covering tape you mentions the dark strip directly on the PC board? I can’t tell how I would attach - glue it over the existing strip perhaps? How would I connect it to the traces?
