I’m repairing a Roland AX-1 keytar for a friend. The original problem was that the pitch bend ribbon sensor (“slider pot,” Roland part number J3339102) has reportedly worn out to the point where it does not return to center, a common issue. The previous owner attempted a repair, and somehow damaged the FFC connecting the neck control board to the motherboard (1.25mm 16-pin FFC, 42cm length, Roland part number J3469146).
The perfect repair would involve simply replacing both these parts, but I can’t find either.
Syntaur does carry a replacement ribbon sensor for the AX-7 and AX-Synth. If this is reasonably close to the same size, I can probably hack it in. I wonder if anyone can provide a datasheet (or at least the dimensions and resistance value) of this part? Or, does anyone know if the AX-7/AX-Synth pitch bend controller is about the same size as the AX-1’s?
The alternative is to just disconnect the pot and add fixed resistances to keep it at center. Can anyone explain how this so-called “slider pot” actually works? It has 3 pins, and I get a roughly constant ~6.3K between the top two pins and the expected split on the wiper when touching the ribbon, but a much higher ~110K resistance to the wiper from both ends when not touching the ribbon. These values actually seem fine, in the sense of “returning to center” on my multimeter, but I can’t test it without the FFC repair and have to assume the seller tore it open for a reason.
Thanks in advance for any help!