Isolate the problem, is it drive or recovery?
Turn the amp on and the reverb up part way. Now with the cables unplugged from the reverb pan, touch teh tip of each plug. One should make hum out the speaker. It is the return cable that should plug into the OUTPUT jack on the pan. If neither plug makes hum, your recovery circuit is not running.
likewise test the drive circuit. COnnect the drive cable to another amp. anything coming out the drive cable? Or scope it.
SInce the pan measures OK, it likely is. So connect the INPUT cable to the pan and have the amp trying to drive it. COnnect the OUTPUT of the pan to some other amp. Just plug a cord right from the pan out jack to the input of some amp. IS the pan being driven?
Once we know which half of the system has the problem, it will be easier to start tracking it down.