I made some progress tonight. I have similar situation to OP: slides laterally, back tilt works, vertical adjust non functioning BUT I hear no sound or click when trying either the font or back vertical. I unbolted the seat to get a better look. I was able to unhook the power connection to the lateral motor and hooked up to the front vertical motor and was able to lower the seat. Unfortunately couldn't reach to the rear vertical motor. Will have to look into troubleshooting/replacing the switches and/or supplying power to the rear motor. Couldn't figure out how to manually adjust.