I would say your going to have to deal with Mesa. But out of curiosity do you know how or why this happend?
Barry, sorry for the late response and thank you for replying it.
Just to give you an update (I'm still having trouble with this amp).
Unfortunately, Mesa does not have this board for sale. I guess they don't produce it anymore not even as a replacement kit.
I called a famous amp maker here in Brazil and he replaced the power tube board with some cables and solder direct into the other boards. The amp worked for a while but with a hum, noisier than before, the other techs could not bring a solution to this issue. Did some tests with him and he said the power session was ok. Replaced all the 7 preamp tubes without success, the noise was still there.
Problem #2: Now the amplifier is turning on, all the tubes are working, it is not burning any fuse but no sound at all. Replaced the fuses, plugged the guitar in the return as a test and no sound. I tried everything I could. The tech will be taking a look at it again.
The first problem started when my wife was cleaning the room and by accident she left the standby switch on, I did not see it and turned the power on to start playing. That is it.
The tech said a power tube failed. Replaced the pair with Winged C.