Missing voltages [resolved]

olegreg · 3528

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Offline olegreg

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on: November 21, 2022, 09:19:27 AM
I am doing post assembly tests. Resistances were fine.
DC volts at 1A & 1B fine
OA thru OkB all are 0 VDC
Whats up?
Greg
 
« Last Edit: December 01, 2022, 02:20:54 PM by Paul Birkeland »


Offline Paul Birkeland

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Reply #1 on: November 21, 2022, 12:56:18 PM
This is most likely a soldering issue on that front C4S board.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline olegreg

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Reply #2 on: November 28, 2022, 08:56:50 AM
You were correct, I found a couple bad solder joints on my 3rd inspection.
New issues on separate post.


Offline olegreg

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Reply #3 on: December 01, 2022, 06:08:07 AM
I went to run the system this morning and no sound or anything from EROS 2. All VDC are good except OKA & OKB
which are at 0 VDC. It ran perfectly last evening.
I am at a loss...


Offline Paul Birkeland

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Reply #4 on: December 01, 2022, 06:12:38 AM
I would be looking at the shielded twisted pair wiring that feeds pins 4 and 5 on each of those sockets.  That's about all the EF86s share between the two, and something like this is likely a flaky solder joint.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Doc B.

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Reply #5 on: December 01, 2022, 08:50:28 AM
Maybe remove and reinsert the tubes too. Might clean some oxidation off and/or help to show where a weak joint on one of the tube socket terminals is.

Dan "Doc B." Schmalle
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Bottlehead Corp.

Offline olegreg

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Reply #6 on: December 01, 2022, 02:09:21 PM
You guys nailed it! I re-flowed all the heater connections and yes, that did it.
Thank you, gentlemen.


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