[Amps] Amp problem

[n8de at thepoint.net]

A minor(?) problem has begun with my Dentron DTR-2000L amplifier.

When transmitting on SSB, it sometimes just 'turns itself off'.   
Completely!  No power supply voltage .. no filament voltage .. no dial  
lamp voltage.

Turning off all switches ... and waiting a few seconds .. .I can turn  
it back on and it operates normally.

This has only occurred twice in the past week .. but it's a bit  
puzzling and frustrating.

Any ideas?

73
Don
N8DE