I pulled the trash compactor out from under the counter.

I took out the four screws that kept the top cover in place to expose the ram.

The gear shafts were turning but the ram would not lower, at first I though the ram drive bolts were stripped and it wouldn't engage the shaft. Then I realized there was a mechanical directional\limit switch at the top that controlled the power and direction the gear shafts were turning, this switch was broken.

Just had to take off the front plate that was held on by a number of screws and replace the switch that was held on by two more screws. It had five wires attached to it, the new switch was clearly labeled as to which color wire went where.

Pulled the Compactor from underneath cabinet, unplugged power. Removed the top plate off compactor to expose the crush piston. Removed the front control panel by removing two phillips screws, wiring and directional (limit) switch is now exposed. Removed the two screws securing switch, removed wiring one wire at a time and replaced on new switch in same position. Replaced switch in same manner as removed, and followed reverse of above to re-assemble. Plugged back in and tested, problem resolved works like new. Only took possibly 30" to repair and saved an expensive service call.

I slid the compactor out of the cabinet space it sits in and unplugged it. I removed the two screws that hold the control plate on and it then lifts up and off to reveal the screws that hold the top down. Then I removed the two screws that hold the top of the unit on and removed the top. I then put the switch plate back on and plugged the unit back in and ran it so I could see it operate from above. It went all the way down compacting the drawer but kept running and did not reverse and come back up. I figured it was the directional switch and ordered that. The plastic power nuts that the unit rides up and down on looked worn so for $10 each I ordered a pair of them also. The parts arrived in 3 days. I decided to install the power nuts first. When I removed the metal casing that holds them I saw that wings on the plastic power nuts that hold them in place in the metal casing were all broken off. I installed the new power nuts then plugged it back in and ran it. It cycled perfectly. luckily I had not opened the directional switch and I was able to return it to Partselect for a refund. In total I had to remove and reinstall 4 very short screws and 4 small bolts. While I had it out and apart I also cleaned out quite a bit of old trash that had escaped to unseen parts of the compactor. It is 26 years old and working fine. I don't think they make them like they used to. Thank You Partselect for a great experience

Took off front panel and replaced the directional switch which I thought was the problem. However, the problem continued. I read on line it could be the "centrifugal" switch on top of the motor. I haven't gotten around to taking it apart yet to see if that is the problem because it is more involved down under and in the back. That switch cost $88.
Any suggestions from others?

replaced switch and fixed the problem. Still had one more problem after that though, but got that figured out and fixed that to.

Removed two screws on the front panel cover and lifted off the cover , removed two small screws on the switch bracket, you need a short nut driver, removed the spade clipped wires from the old switch and replaced them on the new part and thats all there was to it.

I broke the directional switch trying to replace the power nuts..duh huh... ordered a new switch, took off the front panel ( 4 screws) replaced the switch (2 bolts) be careful not to lose the small threaded plate used instead of nuts to secure the switch.. and now it works like new again....partselect is a great resource for the diyer

changed out the switch and that fixed the problem

Put the parts in and reinstalled it back in it place