Integration high voltage

[Karl5150]

  The complete rebuild of my Reduction was successful, the Integration was not. I used the boards from he original build. The SR board is fine but 2 LEDs on the C4S board installed on the B/Left channel side don't light and the voltage to OA was high.
  Thinking the board would likely need to be replaced I swapped it end for end for S&Gs. The OB then read high and that half's LEDs didn't light but the OA half's did.
  Did a visual and resistance check of the tube and RIAA wiring (trying to compare the A B sides to each other) and couldn't find anything a-miss.
  Related voltages:

      2 - 72V
      4 - 105V      OA - 68V  OB - 73V
  7/15 - 66V
____________________________________________________

18/26 - 101V
    29 - 104V      OA -101V  OB - 69V
    31 - 64V

Where should I be looking?
Thanks for any guidance,
Karl.

 

[Paul Birkeland]

I am guessing that you are also experiencing an LED on the 9 pin socket that isn't illuminating? 

My strongest suspicion is that somewhere along the path of the bare buss wire on that side of the amp that goes out from the ground lug and snakes its way around, you have a flaky solder joint.  Things were OK enough in the original build, but when installing the integration you have nudged a wire loose and you need to go over the build and figure out where this is. 

-PB

 

[Karl5150]

Thanks Paul, I'll look more closely at that.

 

[Karl5150]

Paul,
  While both LEDs on the socket were illuminated, a second (and third) look and some probing with chopstick turned up a bad joint where I had removed one of the 18K resistors for the C4S install. Thanks for keeping me on task.
  Related, I remember the terminal strips I used in the rebuild were difficult to work with, particularly the lower holes. I wiped them with denatured alcohol with some, obviously limited, success.
Thanks again,
Karl