NAD, but we have a problem!! HELP!!

[rdamato]

Got a Mesa F-50 from a TGP'er today. Arrived in good shape! Put the tubes in and fired her up and strummed a few chords. YIKES!!!!! Sounded painfully thin to me. I took out my bias probe and got 31Ma on V5 and 0 Ma on V6. switched tubes, changes tubes and got the same result. V5 get as hot as expected while V6 lights up, but barely gets warm.So, I presume I have a problem. I've contacted the seller and do not anticipate a problem, but I want the amp and would like to get it repaired.

Any ideas what the problem may be???

Thanks in advance,
Ron

[Firestorm]

0mA on V6: I'd suspect an unconnected V6 cathode or dead OT.