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Problem with high grid voltage on TSE 300b amp.

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The right side grid voltage on the output tube socket is over 400v

Some background.

I built amp abt 3yrs ago. It worked for 6mos to a year. Initially had heat issues with the 5v regulator overheating and shutting down. I think I've resolved that.

When it stopped working the right tube blew. I replaced the tube and it worked for a bit, then failed again. When I was troubleshooting (2yrs ago) I remember having trouble not being able to adjust the grid voltage, so I ordered some resistors, the mosfets and the CCS's. But I haven't gotten around to working on it till now.
I fired it up, starting with the checkout .

The filaments tested ok, then after putting in the rectifier, it appeared to becoming up fine. but at some point it started smoking. R14 (36k) was failing.

I replaced r14 and q1. r14 smoked again. two of the pads on q1 seemed questionable (middle one looked ok)after i had removed them, so I just jumpered from the lead to one side tp r34, the other to c9.

That seemed to stop the smoking r14. I was able to get to checking the grids and was getting 400v on the right grid -128v on left. Then I swapped out U2. I'm still getting 400v on the grid, and I think i'm smelling r14 is staring to burn again.

Ceckout values so far with just the rectifier in
Filaments 4.9v
B+ 450
left grid -128
right grid +400 (may go higher but I switch it off)

So where to do I go from here?

plan B is starting over with a new board, but I'd like to get this one working if I can.
I'm struggling to visualize how you can have a positive voltage of any magnitude on one grid, while the other is negative.

The grid with the positive voltage sounds like it's shorted to the B+, possibly through a shorted tube or bad socket.

The side with the large negative voltage sounds like the FET is blown.

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