I have a univox u-1246, 70's tube amp head. It keeps blowing fuses and not working when i switch from standby to on. I have tried new power tubes and that didn't help. Any advice would be awesome!
Take it to a professional, sounds like an internal problem and there is a very high risk of electricuting yourself in amps due to capacitors n stuff.
Main Gear:

Santiago S3 Spanish Classical
PRS CE22 Mahogany
Mesa/Boogie F-50 combo w/ G12K-100
Teese RMC Wizard Wah
Rothwell Switchblade
Ibanez FL-9
Visual Sound Liquid Chorus V2