The owners manual indicates that there are a couple of internal fuses. These would likely be under the chassis. I assume the fuse you did change was the one where the main power cord plugs in(?)
Since the tubes glow, I'm going to assume that the main power transformer is working. The main transformer supplies voltage to the tube filaments, the B+ high voltage for the tubes, and low voltage power supply. Since all the panel lights don't come on and those may all be low voltage LED's, it might be something wrong with a low voltage DC power supply that provides power for the solid state electronics of the amp, such as MIDI, effects, and switching controls. This would likely be fused with an internal fuse under the chassis. I wouldn't recommend you try to troubleshoot this unless you have some knowledge of electronics and this unfortunately probably means a trip to the amp doctor. Any chance the amp may still be under warranty?
**There can be stored voltages under the chassis that can injure or kill you!!**
Although I seriously doubt it can help, but there is a factory reset procedure on page 21 of the owners manual (downloaded from their site). It might unlock something that got stuck.
