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October 05, 2022, 04:39:41 AM

Author Topic: Voltage check problem [resolved]  (Read 168 times)

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Offline BillB

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Voltage check problem [resolved]
« on: March 10, 2022, 08:55:47 AM »
Hello, I ran the voltage checks on my StereomourII build, and all the numbers came out very close except for #7. My meter reads 0. It should read 170_230 VDC. I ran through the entire build step by step again and found no bad solder joints, touching wires, or mistakes. Any suggestions? Thanks much.
« Last Edit: March 10, 2022, 02:53:10 PM by Paul Birkeland »

Online Paul Birkeland

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Re: Voltage check problem
« Reply #1 on: March 10, 2022, 09:04:02 AM »
This may be fairly easy to debug with a couple of build photos.

What DC voltage do you get at IA on the C4S board?
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline BillB

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Re: Voltage check problem
« Reply #2 on: March 10, 2022, 09:10:27 AM »
Paul, I get 410.

Online Paul Birkeland

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Re: Voltage check problem
« Reply #3 on: March 10, 2022, 09:11:49 AM »
Some build photos will probably help here.

-PB
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline BillB

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Re: Voltage check problem
« Reply #4 on: March 10, 2022, 09:27:34 AM »
Here's the photo Paul

Online Paul Birkeland

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Re: Voltage check problem
« Reply #5 on: March 10, 2022, 10:06:47 AM »
If you pull the 12AT7 out of that side, does the voltage pop up?
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline BillB

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Re: Voltage check problem
« Reply #6 on: March 10, 2022, 10:30:04 AM »
No change after pulling 12at7, still 0. I earlier switched the 12at7 tubes, still 0.

Online Paul Birkeland

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Re: Voltage check problem
« Reply #7 on: March 10, 2022, 11:24:37 AM »
This is very likely to be a solder joint issue on the C4S board.  I would reflow all of the joints other than the ones for the LEDs (they don't take much heat to solder properly).
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline BillB

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Re: Voltage check problem
« Reply #8 on: March 10, 2022, 02:01:14 PM »
 Paul, good call! All the voltage numbers check out. Thanks for your expertise.