Drip Pultec EQ problem
« on: October 17, 2019, 10:39:03 AM »
Hey everyone,

Im looking for help with this EQ ver3.  It was up and running smoothly for over a year, and then it stopped working.  When I opened it up, I noticed a burnt 2.2k resistor so I swapped it out.  Now the same resistor keeps burning up and smoking within a second of power up.  Ive even tried throwing new tubes in just in case the tubes died, and no change.  I figured maybe there were some damaged components so I swapped every resistor, capacitor, and diode in the power section.  I am STILL getting a burning resistor when I power it up, and Im ready to throw this thing in the garbage.  It is the 2.2k resistor that lives next to the 345V test pad and between the 47Uf caps.  Ive attached some pics for good measure...  Anyone have any ideas to try??  Thanks.



Re: Drip Pultec EQ problem
« Reply #1 on: October 17, 2019, 10:41:31 AM »
Pic of burnt resistor

Re: Drip Pultec EQ problem
« Reply #2 on: October 17, 2019, 10:43:34 AM »
Pic of whole board

Re: Drip Pultec EQ problem
« Reply #3 on: October 17, 2019, 10:44:49 AM »
Schematic

3nity

Re: Drip Pultec EQ problem
« Reply #4 on: October 17, 2019, 04:33:44 PM »
Did you replaced that 50uf capacitor right after the 2k2? Have you tried disconnecting that cap? Have you disconnected the output transformer?
Life is a path, death the destination.

Re: Drip Pultec EQ problem
« Reply #5 on: October 17, 2019, 05:03:08 PM »
Did you replaced that 50uf capacitor right after the 2k2? Have you tried disconnecting that cap? Have you disconnected the output transformer?

I've replaced all the caps, but I haven't tried disconnecting the output transformer.  I wasn't sure if it would harm the unit...  Ill get back shortly!

Re: Drip Pultec EQ problem New
« Reply #6 on: October 17, 2019, 05:25:59 PM »
Did you replaced that 50uf capacitor right after the 2k2? Have you tried disconnecting that cap? Have you disconnected the output transformer?

Just tested without the output transformer wired in, and nothing is smoking or burning!!  Hooray! 

I tried resoldering all the leads to the output transformer back into the circuit to test again, and the smoke came back.  I am also getting new smoke from the 470R resistor right above the diodes. 

Does this indicate a bad output transformer??
« Last Edit: October 17, 2019, 09:38:47 PM by wimmy7986 »


 

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