Enzo,

Thanks for the post. 

Does not pass the guitar signal.  None of the controls effect the hum.  Speaker is totally silent.  I've now tested the speaker and it's good.  As soon as I can I'll take the board out and look for cold solder or broken solder joints.

Let me know if you have any other ideas.

Wife bought me a DOA FM25DSP for $50.  I live 70 miles from a good amp tech and I don't think it's worth spending amp tech money on, but I would like to fix it for fun.  I have the schematic and some good basic tools temp controlled sodering iron, soder sucker, etc...  Would one of you gurus be able to guide me where to start.  Amp has power light, voltages right coming from transformer but no signal to speaker.  Have hum to headphones when attached.  Schematic attached.

Any help would be appreciated.