My technics se hd 51. My technics se hd 51 amp seems to have stopped working. I have a barely

Question

My technics se hd 51 amp seems to have stopped working. I have a barely audible sound when turned up to full vol. Any suggestions...can I d.i.y. this job ?many many thanks.Technics SE-HD1 Stereo amplifier as part of receiver, cd and tape component system. Haven't used it for a while. Everything seems to be working ok, but no sound coming out of the speakers. Get sound out of headphone jack ok.