Failed Resistance Check

billygood · 2229

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Offline billygood

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on: May 10, 2017, 01:13:00 AM
Just finished my crack and Did the risistance check and passed all but terminal 6 and 10

They should both be 0 but both read 2.48k/2.49k

I went back through and checked and to my eye everything looks good.

What would cause this? Both point 7 and 9 checked out fine at 2.9k

Thank you in advance.



Offline fullheadofnothing

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Reply #1 on: May 10, 2017, 07:30:56 AM
Post pictures.

Joshua Harris

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

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Reply #2 on: May 10, 2017, 04:17:02 PM
Here are some pics



Offline fullheadofnothing

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Reply #3 on: May 10, 2017, 05:50:13 PM
Could you take a clear picture of the headphone jack?

Joshua Harris

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Offline billygood

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Reply #4 on: May 11, 2017, 03:10:41 AM
Here are some.



Offline Doc B.

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Reply #5 on: May 11, 2017, 06:24:40 AM
You may have a cold solder joint where the upper of the two black wires is attached to the headphone jack terminal that is closest to the chassis panel. Try reflowing that connection and remeasure the resistance.

Dan "Doc B." Schmalle
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Offline Paul Birkeland

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Reply #6 on: May 11, 2017, 08:33:33 AM
Just finished my crack and Did the risistance check and passed all but terminal 6 and 10

They should both be 0 but both read 2.48k/2.49k

I went back through and checked and to my eye everything looks good.

What would cause this? Both point 7 and 9 checked out fine at 2.9k

The black wires at the headphone jacks are part of the ground buss.  The 2.49K resistors get shorted out when no headphones are plugged in, and your Crack is not currently doing that.  This is most likely an issue with the solder joints on the headphone jack itself, or terminal 3L.

Until this issue is resolved, do not attempt to power up or use your Crack.
-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline billygood

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Reply #7 on: May 12, 2017, 04:18:02 AM
It was 3u. Thank you all for the help. Now I'm on to the voltage

I had 2 and 4 get 369 (should be 170)
7 and 9 at 240 (should be 115)

One step closer.




Offline billygood

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Reply #8 on: May 12, 2017, 05:14:11 AM
Some pics.



Offline fullheadofnothing

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Reply #9 on: May 12, 2017, 07:25:37 AM
Are the tubes glowing?

Joshua Harris

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Offline Paul Birkeland

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Reply #10 on: May 12, 2017, 10:32:53 AM
It was 3u. Thank you all for the help. Now I'm on to the voltage

I had 2 and 4 get 369 (should be 170)
7 and 9 at 240 (should be 115)
Are you getting 369V, or 369mV?  You can measure a battery to get some familiarity with your meter.

What country do you live in, what was your line voltage, and which setup did you use on the power transformer?

In the absence of any of this being applicable, you very likely still have a loose ground wire.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline billygood

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Reply #11 on: May 16, 2017, 08:24:18 PM
I live in the U.S. and my first volt check was 119v. The tubes and LEDs glow. I had 369v as the reading.
« Last Edit: May 16, 2017, 11:53:58 PM by billygood »



Offline Paul Birkeland

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Reply #12 on: May 18, 2017, 08:10:39 AM
I would zero in on the junction of the black wires that meet at the headphone jack.  I would bet that one is loose and not well soldered in the bunch.  I would also check your solder joint at 3L.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man