I have an older TAPPAN trash compactor M/N 52-2434-10-02 that has stopped working. The ram is in the top, or home position. When I turn the start switch, I can hear the motor "hum" but the ram does not move. If I disconnect the power and manually run the ram down, then re-apply power, the motor starts and returns the ram to the the home position. I see from the schematic on the unit that there are 2 limit switches, plus another switch that control the up/down functions by switching the forward/reverse coils in the motor. I am only assuming that since the motor runs to return the ram to the home position, that it is good. I suspect possibly the upper limit switch may be the cause, but I really need some help. Is anyone familar with this model?