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March 04, 2021, 01:01:07 AM

Author Topic: Failed voltage check. [tentatively resolved]  (Read 450 times)

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Offline andyh

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Re: Failed voltage check.
« Reply #15 on: January 14, 2021, 10:42:26 AM »
Both 173v

Offline Paul Birkeland

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Re: Failed voltage check.
« Reply #16 on: January 14, 2021, 10:53:14 AM »
OK, now measure the DC voltages between 3 and 2, as well as 4 and 2.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline andyh

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Re: Failed voltage check.
« Reply #17 on: January 14, 2021, 10:56:54 AM »
I did move the capacitor near 20/21,  and poked around with the diodes there as you was showing an interest in that area.

So out of curiosity as there is power there I've redone voltage check.

Results are

1 = 94.7v
2 = 172.9v
3 = 0.4v
4 = 173.6v
5 = 90.2

6 = 0.4
7 = 113.2v
8 = 0.7v
9 = 115.5v
10 = 0.4v


Offline Paul Birkeland

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Re: Failed voltage check.
« Reply #18 on: January 14, 2021, 10:58:54 AM »
You may just have a loose connection or two.  Those are working voltages, out of curiosity, can you carefully measure the voltages at A3 and A8?
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline andyh

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Re: Failed voltage check.
« Reply #19 on: January 14, 2021, 10:59:59 AM »
Both 174v

Offline Paul Birkeland

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Re: Failed voltage check.
« Reply #20 on: January 14, 2021, 11:01:01 AM »
No, A3 and A8 wouldn't be 174V.  That is pin 3 and pin 8 on the 9 pin socket.  No pins on the 9 pin socket should read that high (although 1 and 6 will for about ten seconds when you first turn the amp on).
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline andyh

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Re: Failed voltage check.
« Reply #21 on: January 14, 2021, 11:02:28 AM »
Sorry crossed wires excuse the pun,, is that 12u to a3, a8?

Offline andyh

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Re: Failed voltage check.
« Reply #22 on: January 14, 2021, 11:09:12 AM »
2-3 = 174v
2-4 = 0v

Offline andyh

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Re: Failed voltage check.
« Reply #23 on: January 14, 2021, 11:15:41 AM »
I think you meant 3 - a3       3 - a8  are both 1.5v

Offline Paul Birkeland

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Re: Failed voltage check.
« Reply #24 on: January 14, 2021, 11:17:13 AM »
Yes, 3 is a ground.  It looks like your amp is working properly now.  I would poke around with a wooden chopstick and a cheap pair of headphones plugged into the amp to be sure nothing causes a popping noise when you poke around in there.  If you have a loose connection and you poke it, you will get a pop through your headphones and that can help refocus your efforts.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline andyh

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Re: Failed voltage check.
« Reply #25 on: January 14, 2021, 11:18:47 AM »
Thank you so much for your help I really appreciate it.