Peavey Amp Problem?

[mtnb1kr]

I bought a used Peavey Triumph 60 combo at a yard sale today for only $25. It had a broken 6l6 power tube. Brought it home and took a pair of 6l6's out of my Mark IV to try. Amp powered up and seems to operate fine except there is no volume to speak of. All three channels when cranked barely have the volume of a practice amp. All tubes seem good, I even tried changing the 12ax7 driver tube with no luck. Any ideas?

 

[Inearthed]

I'd bring it in to a tech, there could always be another reason it was only $25 at a garage, besides the broken power tube...