peavey xr600b buzzing

[Enzo]

I think your meter is fooling you.

Which power amp is on the back panel? 400BH? 400B/G?

DO your speaker cones move one direction and stay there? If so, turn it off immediately. With no speaker connected, is there DC voltage on the speaker out jack?

Do you have the pair of large blue capacitors? They should both have the same voltage across them, just different polarities in the circuit.

[epping16]

I think your meter is fooling you.

Which power amp is on the back panel? 400BH? 400B/G?

DO your speaker cones move one direction and stay there? If so, turn it off immediately. With no speaker connected, is there DC voltage on the speaker out jack?

Do you have the pair of large blue capacitors? They should both have the same voltage across them, just different polarities in the circuit.

==========
Thanks Enzo really appreciate your help.
The amp on the back panel is 400BH
With no speaker connected there is very minimal DC voltage 50mV, however there is about 1.5V AC. I noticed that when I turned off the power it jumped to 1.2C DC and slowly went down in voltage.

Yes I have the two large blue capacitors, I will check voltage across them and report back to you, am I expecting DC or AC and approximately at what voltage?

Thanks
Joe

[Enzo]

Roughly 50v on each.


50mv is nothing, your amp is not blown on the outputs.

[epping16]

Roughly 50v on each.


50mv is nothing, your amp is not blown on the outputs.

Thanks Enzo, I checked both large electrolytic (blue) capacitors and the one on the edge of the circuit board has 52V DC whereas the other only 16.6V DC, do you suspect this capacitor needs replacing?
Also there is no AC voltage on these capacitors.
Thanks

[Jazz P Bass]

Peavey 400BH

Enzo is on a train trip, so I will jump in here.
First off, the power supply is bipolar.
Meaning there is a + & a - voltage.
You are not indicating that in your readings.
Seeing no Vac ripple cannot be true. (unless you are misreading things, or you have a cheapo meter)
There has to be 'some' ripple voltage. (less than a volt).
If the one cap is indeed reading 16 volts than either one of the rectifier diodes is bad, the cap is shorted or something is drawing it down.
Have you made an attempt to reflow the solder in that vicinity?
I like to reheat the transformer headers, the diodes & the caps.
Not knowing if you have the schematic or not, I have attached it.