Peavey XRD680TB problems after a storm

Probability-wise in those circumstances, whatever can least accommodate voltage surges, so anything requiring a nice low 3.3 or 5V supply ie the main system control micro knocked out first

This unit came in after a big electrical storm. When power is applied you hear a slight hum from the speaker outputs but it does not respond to any input. It seems to be a problem in the output or driver section but this is difficult to trace. Does anyone have a service manual for this? Thanks, Lenny

I assume you have tried injecting a signal into the PAIn1 and 2 jacks and established both Power Amps don't work?

(It might be a mistake, IMHO, to automatically assume the recent storm has anything to do with the current fault)

Gareth.

Peavey will usually email schematics for free. Chuck

On Friday, September 27, 2013 10:35:24 PM UTC-4, snipped-for-privacy@gmail.com wro te:

hear a slight hum from the speaker outputs but it does not respond to any input. It seems to be a problem in the output or driver section but this is difficult to trace. Does anyone have a service manual for this? Thanks, Le nny

I found that Peavey employs several FETs on the inputs to some of the ampli fiers in the unit. These are apparently "sacrificial" components which shor t during an overload thereby protecting the associated IC's. I found three shorted ones. I ordered replacements from Peavey and will see what happens. The clue was that the "X" voltage which is supposed to be -22v was zero. T he shorted FET's essentially shunt it to ground. Lenny