Stereomour voltage check problem

CarlK · 1398

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Offline CarlK

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on: October 22, 2022, 09:16:33 AM
Hello,

I just finished my Stereomour II build but I have run into a few probelms during the voltage tests. All good from the resistance test but something is clearly wrong thereafter. First of all only two out of four led lights shines. The led lights closests to the volume control does not shine. Furthermore, I get zero readings at terminal 34 as well as 36, 39 and 39. Should I presume that something is wrong on the board or do I have the error even earlier?

I have gone through both the wiring and the solder joins and I have not find anything unexpected.

Kind regards,
Carl



Offline CarlK

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Reply #1 on: October 22, 2022, 10:41:37 AM
Just found out that the resistor between terminal 44 to 31 did not give any reading on the multimeter wheras the others do. I presume this would be the issue...



Offline Paul Birkeland

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Reply #2 on: October 22, 2022, 12:04:30 PM
These resistors don't usually open up on their own, but you could certainly replace it to see what happens. 

None of your photos provide a top down view of the C4S PC board, so it's tough to say if there might be an issue with the build there.

If you aren't careful about putting the fat pins of the 2A3 tube in the bigger socket holes, the tube can be forced in the wrong way, then the filament inside the tube will create a short to ground for the high voltage supply on that channel and you could burn up one of those resistors almost instantly.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline CarlK

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Reply #3 on: October 23, 2022, 03:33:36 AM
Thanks for your reply. I was careful with the direction of the tubes but who knows, I might have inserted one tube in reverse nevertheless. I will however begin to replace the resistor and then redo all solderinges around it. Hopefully this will do otherwise I might need som further guidance. Thanks.

/ Carl