Well here is an option,
Pull the cover and look for any obvious burned resistors.
Find one replace it. Chances are thats all it is.
I had a M120 pair like an idiot-- I put in a tube without a Centering pin
Roasted 3 resistors,
I called rogue service told them Didn't feel like shipping it across the country, Serviced said look for any obvious burnt parts, I found 2 resistors replaced them and works fine. Took 10 minutes. Maybe not an option.
Alos might be time to look at a Class D replacement.
Good luck. Rogue has Great service. Have had 6 amps of theirs.
Running Apollos now.