Hello - I picked up a Beomaster 1900 (model 2904) in good physical condition from a thrift store for $10 and figured it was worth seeing if it worked & trying to fix it if it wasn't too hard. The unit powers on and seems to respond to some input - the standby light is lit, and if I touch one of the source buttons the bass/treble/balance lights come on. None of the left or right panel indicator lights are not lit, and I get nothing out of the headphone output. I've done a preliminary disassembly of the unit and it is in fairly good condition internally - it was serviced in the 80s according to a servicing sticker and has been recapped. The lamps all show continuity, so it doesn't seem that they're all out. What would be a good first place to investigate? I might be a bit out of my depth with this project, but I figure for $10 it's a good learning experience. Thanks!