Can't get resistance readings correct on power switch

Ztrains · 1859

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Offline Ztrains

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In both the on and off position I get low resistance. I just replaced the power switch even, after the first time I know I screwed it up. This time I think the joint is pretty solid but I still get low on both on and off. Also depending on where on the joint I hold the leads of the voltmeter I get different numbers. I'm really frustrated as I cannot figure out what is wrong and really want to build this amp but as this is the first real check I can't progress any further.
« Last Edit: August 13, 2017, 04:10:02 PM by Ztrains »



Offline Doc B.

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Reply #1 on: August 13, 2017, 04:16:51 PM
Are the lugs on the switch easy to wiggle? If so the switch has been overheated, which can soften it enough to allow the internal contacts to touch even in the off position.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Ztrains

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Reply #2 on: August 13, 2017, 04:24:57 PM
Are the lugs on the switch easy to wiggle? If so the switch has been overheated, which can soften it enough to allow the internal contacts to touch even in the off position.

They are solid as a rock. The first time I tried it it was super wiggly, so I bought a replacement switch and they're nice and strong now



Offline Doc B.

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Reply #3 on: August 13, 2017, 04:49:20 PM
Can you feel it "click" a little when you throw the switch, or does it just move smoothly?

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Ztrains

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Reply #4 on: August 13, 2017, 04:51:47 PM
There's a solid click



Offline Doc B.

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Reply #5 on: August 13, 2017, 07:44:48 PM
To eliminate any possible issues outside of the switch itself, double check the meter function. Make sure you are seeing over limit when the meter leads are not touching each other, and a very low resistance when the test leads tips are touched together.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Ztrains

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Reply #6 on: August 14, 2017, 05:37:50 AM
Yup the meter is correct



Offline fullheadofnothing

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Reply #7 on: August 14, 2017, 06:30:52 AM
Can you post a picture of your wiring?

Joshua Harris

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Offline Ztrains

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Reply #8 on: August 14, 2017, 06:50:40 AM
This is the power switch joint: (https://lh3.googleusercontent.com/W2lUGpA8g2NTd2f6z0sCG7p_7vDkmCpQ7e-DyATkCp9dMRCT9r7_sGQfNdqZ6DNIMx6yaL4A2mwJ80UULNgh0zyLDBsGI0GJo-dzE0TPecQMU7RPVEbdqaiGNEHQ9Xyii9z2eeGmb2KW_PA03Eu1ZPNrMFE22osclw1iCEReOd1_iM0cQSIU78X19FCdkbi9X2jX0W055aR7qh3pnuGgqG2XgXH5-ocSybkX1K25wOeedIKpOWHeZRzobGVn1Gi0a0d7vCIWnfs9H3s07ZxLaq9A8Cua2nGvL9mR1H2AUJihu537WhApYHBCWN44OKdR--9hxe4kAj8zHcjUBokcPL5ttCRKF-rU155FLDbFfSFM5NSZh7pcyc144MDf51smqLm07fmge3EJ8dhCDZR4pceGrv0DgR6Q7UvuQq2dfSRQonseHKfE_2mZobVMOg87jFBgYXGTX8T9pDYZUvNvv3jSFK5izdGKultr7oXWE-Rkk9iLTRojBBkjNg0kKiPYhV6usMkuFDiMCJfh_cfwMAM8Kn1CywnHqS-pGNQun6p87VyxtNxFmOx6NOCf2-PpzK5lnkl9IMv0rg985SMrT8rtqFYWzfctqtS1bvabmHPsIsEOvNW4=w1029-h1372-no)



Offline fullheadofnothing

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Reply #9 on: August 14, 2017, 08:05:42 AM
1) There isn't a picture there.

2) I'm asking to see if you have miswired something. A picture of just the joint will not be sufficient to see if your wiring is correct.

Joshua Harris

I Write the Manuals That Make The Whole World Sing
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Offline Ztrains

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Reply #10 on: August 14, 2017, 10:49:13 AM
The picture shows up for me, strange. Here is a picture of the actual wiring like you requested:
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fggqsknb.jpg&hash=8c17725f025571795b53b9890a54e8c06f66e48c)



Offline Doc B.

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Reply #11 on: August 14, 2017, 11:00:04 AM
Looks OK, so it might simply be an issue of overheating the switch again. Just to be thorough - you are testing with the black lead on one switch terminal, and the red lead on the other switch terminal, yes? Please understand I don't mean to be insulting with this question, it's just that the instructions are not quite that explicit and I want to be sure to cover all the possibilities.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Ztrains

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Reply #12 on: August 14, 2017, 12:11:26 PM
Ah that might be the problem. I have been touching both leads to the same terminal. I'll go try out the correct way now.



Offline Ztrains

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Reply #13 on: August 14, 2017, 02:53:56 PM
That was in fact the problem. Thanks Doc B! ;D