I recently bought a used Hafler Pro 1200 power amp. When I plug it in and turn it on, the power switch does not light up as its supposed to, but when I put my ear to the amp I hear a quiet humming so something turns on. I connected a banana plug into the two red connectors (both +) as instructed by the manual because im using a mono output. I connected the other end to a 120 watt 16 ohm guitar cabinet. The power amp is actually 8 ohms but I assume it would work fine as long as the cab is greater or equal resistance. I plugged my guitar directly into channel B of the power amp, turned up the volume and tried to make noise.

AND DRUM ROLL PLEASE....... it didnt work. Any thoughts? It might be something stupid because Ive never used a power amp before. Maybe a blown fuse? Help? thanks