Princeton Rev. Bias Circuit problem

[mresistor]

Well  I have a very puzzling problem. I have a PR on the bench and I've replaced ALL the electroytics. I have added the 50K piher trim pot to the bias board as per Dougs instructions with a 10K resistor soldered to the left lead with the other lead of the 10K r to ground. I've got a 70uf 100v electrolytic in parallel with the 10K r and the 1/2 of the trim pot. I've done this same thing to other PR's before successfully. With power on I have around 356 vac on the 100K resistor but I'm only getting around 7.5 -12 vdc out of the curcuit with the lead to the grids on the intensity pot (center lead) disconnected or with it connected.  I pulled the board back out and checked the diode and it checked good. I disconnected the cap and measured from the ground side of the 10K to the center lead of the trim pot and it adjusted from 10k to 60K. I subbed in another filter cap and got the same results. The only thing I can think of is that the diode must be faulty in circuit.
I'm taking a break from the amp and thought I'd post this.  I'm considering replacing the diode.
What do you all think?


Not: when I got the amp the speaker was seized and had open coil. The OT had an open primary winding. And the PT had smoked like a campfire. They have been replaced,

[mresistor]

I lifted one end of the 70uf 100v cap and now I have the correct adjustable bias voltage.  I have subbed in another of those 70/100 electrolytic caps and it did the same thing. Bad batch of caps?
This is strange.

[mresistor]

Ok I subbed in a 47uf 250v electrolytic and the bias adjusts fine, so definitely a bad batch of 70uf 100v capacitors. I have never experienced this and sorry to take your time.