GLD Fader readout jitter

I’m having a strange issue on my GLD. After I turned it back on after a year or so all fader values are jittering around. Not the physical faders (they move correctly and stop moving once they’ve reached their position) - just the value readout of the fader jumps around.

This happens on all fader banks, regardless of the physical fader position. So I suspect something in the fader readout A/D conversion and/or powersupply?

Anyone had something like this before?

Here is a screencap of GLD-Edit showing the jumping values:

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