Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: plexi50 on March 17, 2012, 06:58:15 pm

Title: Blues DeVille PI Problem
Post by: plexi50 on March 17, 2012, 06:58:15 pm

Hello all! Long day as usual. I have a Fender Blues DeVille that has a PI problem. I have 215VDC on pin 6
I have -0- volts on pin #1 /
 :help:

Title: Re: Blues DeVille PI Problem
Post by: bruno on March 17, 2012, 07:28:15 pm

I once fixed a blues deville that had that same problem, no voltage on one of the plates, I traced the problem to the resistor feeding that plate, because there was voltage before it. It turns out the resistor was open, and fender had a problem with a batch of bad resistors,  and several of those amps ended up developing that same issue.

So check for an open resistor that feeds the plate #1 of the PI.

Title: Re: Blues DeVille PI Problem
Post by: plexi50 on March 17, 2012, 08:15:03 pm

Thanks Bruno. I found it. R51 91K plate resistor. Sounding good again. I also found an illinois PS cap that was blown open at the pos lead. Interesting day. Happy Green whatcha call it day! St.Patricks day. Does that mean it is mandatory to drink tonight? I dont wana :l2:

Too late. I went to get cigarettes and B. Green Beer

Title: Re: Blues DeVille PI Problem
Post by: bruno on March 18, 2012, 05:25:57 am

Cool! Happy St Patricks!  :occasion14: