Peavey XRD680TB problems after a storm
 

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

Peavey XRD680TB problems after a storm
 

On 28/09/2013 03:35, wrote:
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



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

Peavey XRD680TB problems after a storm
 

wrote in message
...

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 XRD680TB problems after a storm
 

On Fri, 27 Sep 2013 19:35:24 -0700 (PDT),
wrote:

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


Peavey will usually email schematics for free. Chuck

Peavey XRD680TB problems after a storm
 

On Friday, September 27, 2013 10:35:24 PM UTC-4, wrote:
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 found that Peavey employs several FETs on the inputs to some of the amplifiers in the unit. These are apparently "sacrificial" components which short 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. The shorted FET's essentially shunt it to ground. Lenny