Peavey 6505+ 112 Combo - Lead channel problem

[PeanutNore]

I've been having issues with the lead channel on my 6505+ combo that I bought in March. I took it to the dealer in April for a warranty repair, but they didn't get it back to me for months. I know enough about electronics to work inside a tube amp safely, but I figured it would be free (it was), so I let them repair it. A couple weeks after I got it back, more problems with the lead channel. At the same volume setting as rhythm, it is much quieter. I figured it was a problem around V4, the last tube in the signal path in the lead channel, and yeah, the dealer definitely made a repair there.


http://i.imgur.com/LUvGt.jpg

After insuring the caps were drained I did a little continuity testing and measured a few resistors. R57, the one with the white spot, and R58 next to it both measure at 533k ohms - am I right to assume there must be a short on the underside of the board?

I can't find a schematic for this amp anywhere, so I've been going off of other 5150 type amp schematics. If anyone has one they could send, that would be amazing. Peavey has yet to reply to my email requesting information.

[Enzo]

Peavey customer service is usually very responsive. Give them a few days.

R57 is a 1meg to ground. R58 is also a 1meg providing some negative feedback. It goes from a common point with R57 - a tube grid at V4 - through 129k of resistance also to ground. So the two are in parallel with the addition of 129k in one leg. So 1 meg and 1.129meg in parallel should result in something over 500k, which looks like what you got.

Not sure why they would airborne those two parts, the trace that connects them appears intact right under them.