DX7 Data Slider Weirdness

[jack33001]

Hello,

First post here so I apologize for any screwups ahead of time.

So... I've got this DX7. I picked her up a few months ago for $200, had a scratchy volume pot and a data slider that acted weird. I thought 'oh easy, I'll just replace the volume and data pots and have the working DX7 for like $250!' As it always seems to go, that wasn't the case. The volume slider was fine - replaced the part, works like new now. The data slider - not so much.

I've replaced the slider twice now, in order to rule out a faulty replacement part. Moving the slider doesn't change the value, except for on rare occasion when it'll make a big jump. I've traced the signal path from the pot to the jack to the main board with a multimeter, so I know there are no discontinuities up until the main board. The way its acting just feels like a connection issue with its intermittent functionality, so that's the nature of stuff I've tried so far. The battery is at about 3 volts, and putting the thing into test mode verifies that all other parts are working. So, in conclusion:

Help!!! I can't figure out what the heck is wrong with the data slider on my DX7!