Bottlehead Forum

Bottlehead Kits => Stereomour II => Topic started by: BillB on March 10, 2022, 08:55:47 AM

Title: Voltage check problem [resolved]
Post by: BillB 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.

Title: Re: Voltage check problem
Post by: Paul Birkeland 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?

Title: Re: Voltage check problem
Post by: BillB on March 10, 2022, 09:10:27 AM

Paul, I get 410.

Title: Re: Voltage check problem
Post by: Paul Birkeland on March 10, 2022, 09:11:49 AM

Some build photos will probably help here.

-PB

Title: Re: Voltage check problem
Post by: BillB on March 10, 2022, 09:27:34 AM

Here's the photo Paul

Title: Re: Voltage check problem
Post by: Paul Birkeland on March 10, 2022, 10:06:47 AM

If you pull the 12AT7 out of that side, does the voltage pop up?

Title: Re: Voltage check problem
Post by: BillB on March 10, 2022, 10:30:04 AM

No change after pulling 12at7, still 0. I earlier switched the 12at7 tubes, still 0.

Title: Re: Voltage check problem
Post by: Paul Birkeland 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).

Title: Re: Voltage check problem
Post by: BillB on March 10, 2022, 02:01:14 PM

 Paul, good call! All the voltage numbers check out. Thanks for your expertise.