Yamaha A15 amp

millerman 3732

I was in one of dads old shops fooling around and found an old Yamaha A15 amp and a T15 am/fm tuner on a shelf looks like it had been there a while to, the things where covered in cob webs and saw dust, but I took them home and cleaned them up took them apart and checked to see if I could find any black spots on the boards and I had to change the fuse in the amp. every thing lights up like it supposed to and all the buttons seem to be working but there no sound and the output meters on the front of the amp aren't doing any thing either. Anybody know what might be wrong with it or if its even worth trying to fix?