I recently repaired a Ten-Tec Omni VII for a local friend. All 3 of the encoders on the LH side of the screen were erratic, the pushbuttons associated with them were non-functional, and the encoder on the RH side for RIT/XIT only moved the freq down, no matter which way the knob was turned. I repaired a couple of hairline cracks in the LH encoder pcb, replaced a 1uF cap that was leaky, and replaced one switch assembly. I was able to disassemble the RH encoder and clean / service it. With each repair, it has to be reassembled to test... Here's a few pics and vids:
