[quote name='4 Strings' timestamp='1327189213' post='1507735']
Thing is, my HA5000 is two separate power amps. If I only use one cab, one power amp is running with no load on it. This is the case for the majority of its life.
[/quote]
Perhaps the non running amp is automatically switched out of circuit, but then again, with todays technology anything could be happening.
I always err on the side of caution with amps having had one blow mid gig at a major outdoor festival because a silly sound engineer tripped over my speaker lead and disconnected it. Resulted in costly serious damage to the output stage of the amp.