[Motoman]

If you think the switches in the panel are intermittent, i.e. you indicated the panels sometimes indicates, you might get some electronics spray cleaner and spray it in the switches as you work them back and forth. Make sure you buy a cleaner that is made for plastic so it doesn't damage the panel or knobs. Re-calibration of any pot or rheostat may be necessary afterwards.

You can try a Radio Shack but most seem to be just cell phone shops now days, An industrial electronics supplier like Electronics Warehouse would be a good place to look and they might offer some help in selecting a spray electronics cleaner.