Amp acting up...

[toolshed]

Got a mesa express 2x12. None of the preamp lights are coming on. The power tubes come on and two of the preamp tubes come on. Fuse is good. What should I check next

 

[Jeff Gehring]

If none of the LEDs or pilot lamp are illuminating, perhaps you have had a failure of the regulated 12V supply. That would mean take it to a tech.

 

[Ampmadscientist]

Got a mesa express 2x12. None of the preamp lights are coming on. The power tubes come on and two of the preamp tubes come on. Fuse is good. What should I check next

Yeah,
it seems like the low voltage supply has failed.
Expert soldering is probably required.

Don't try to work on a Mesa amp without test equipment and considerable experience.