It's an optical based assembly, that much I remember off hand. It has a plate with notches that passes between two sets of optical sensors if I remember correctly, one for high gear and one for low, so it may be as simple as dust being stuck between them or just a poor connection/broken trace on its small circuit board. Either way it should be an easy fix, there's not much circuitry involved, at least at the pedal itself.
As far as pics I might need some of the monitor, how it mounts and how to video board connects to it might be useful, mine came without the screen and with some adaptation I'm probably going to give it one from a Monaco GP. If you ever stumble upon a source for side art too let me know, although I get the impression nobody reproduces it.