Well, the power supply is in and the amp powers up and works. There is still a hum but about 1/100th of what it was, will have to try and track that down. The vibrato works. One of the clips that hold the end of the springs in the reverb tank is broken, don't think I can fix that. The reverb unit is not hooked up and the in and out are just hanging loose in the amp, don't know if that would cause any hum? Don't think so. But, so far, so good. Bought two new 7189As from ebay for 25.00. Made in the old Yugoslavia.