duantro

Re: 525 build thread
« Reply #640 on: March 20, 2020, 03:22:04 PM »
Sorry I meant i was probing on A1. corrected that typo.  I'll try lifting the wiring from A1 output to the output pot and see if signal comes back
Edit: I lifted wire labeled #1 from meter board, assuming it is the connection from A1 output to the output pot. It sure is fun trying to figure out where all these traces lead without any schematics correlating to the off board pcbs, besides 1 goes to 1,...Anyway I am still not getting VAC on output of A1. I'll try to reflow some solder on the pins of A1sockets...
« Last Edit: March 20, 2020, 04:35:51 PM by duantro »


duantro

Re: 525 build thread
« Reply #641 on: March 20, 2020, 05:10:17 PM »
That didn't do anything. swapped out 2520 yet again- nothing. I'm geting +_15vdc on A1 pins. Found a broken ground wire that went to SW5A pos 0,.... got excited,... re soldered, and still nothing. Must have been a casualty from all of the assembling/ disassembling. A ribbon connector ala 4kcc sure looks smart now. I'm going to have to walk away...
« Last Edit: March 20, 2020, 05:15:51 PM by duantro »

dmp

Re: 525 build thread
« Reply #642 on: March 20, 2020, 05:13:22 PM »
Did you pull A3?
Swap Q1?

duantro

Re: 525 build thread
« Reply #643 on: March 20, 2020, 05:20:14 PM »
Yes, pulled A3, and just swapped Q1, I know it's got to be something simple, but I'm at a loss

dmp

Re: 525 build thread
« Reply #644 on: March 20, 2020, 05:26:00 PM »
What value is R7 trimmer?

dmp

Re: 525 build thread
« Reply #645 on: March 20, 2020, 05:27:50 PM »
Something around A1 is messed up. Since you have another one that works, compare everything around there.

duantro

Re: 525 build thread
« Reply #646 on: March 20, 2020, 05:34:48 PM »
R7 is 5k. It looks like I'm not getting input to A1 Let me trace through it. Thanks for all of the suggestions.
Edit: A4 does check out. Signal is making it to  the side towards the edge connector of R1
« Last Edit: March 20, 2020, 07:22:30 PM by duantro »

duantro

Re: 525 build thread
« Reply #647 on: March 20, 2020, 07:41:34 PM »
Q5 emitter- base gives me .6vdc


 

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