Resistance Problems Back Again (solved)

dawnchorus · 1763

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Offline dawnchorus

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on: September 01, 2016, 12:21:47 PM
Hey again,

Last night I posted a thread that I had some issues with my resistance readings. I fixed a jumper that I was missing and a bad solder joint and then everything seemed to work. Today, I rechecked the resistance readings before continuing the the voltage check and I got the same errors that seemed to be fixed last night plus some new ones.

Also to note: I painted my transformer bell cover with ceramic enamel paint. Not sure if that affects grounding which might make my resistance measurements off. I also did the revision on page 19 of the Crack manual which connects the 3" black wire to Terminal 14U instead of 22L for quieter operation.

Here are my readings the issues are Terminals 2,4, 14, 20 and the right RCA ground lug. (sorry about the shitty formatting, can't seem to fix it):

Terminal       Resistance        Actual
         
1              *                       22.4K ohms
2              *                       0.2k ohms
3              0 ohms               0
4              *                        0
5              *                       22.4K ohms
6              2.4K ohms          2.4K ohms
7              2.9K ohms         2.9K ohms
8              0 ohms                0
9              2.9K ohms             2.9K ohms
10              2.4K ohms           2.4K ohms
12              0 ohms                0
13              * climb 270K        climb 270K
14              0 ohms                climbing to ~50K ohms
20              0 ohms                climbing to ~50K ohms
22              0 ohms                 0
         
B3              2.9K ohms                 2.93K ohms
B6              2.9K ohms                 2.95K ohms
         
RCA:         
Ground lug   0 ohms                  L: 0   R: Error
Center pin      90-100K ohms          L: 107.5   R: 103.8



Any help would be greatly appreciated!
« Last Edit: September 01, 2016, 05:21:52 PM by dawnchorus »



Offline Paul Birkeland

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Reply #1 on: September 01, 2016, 01:39:08 PM
Terminals 2 and 4 are connected by a piece of wire.  If the piece of wire is there and well soldered, they cannot have a different resistance reading.  If they do indeed have such a wildly different resistance reading, then the piece of wire is not well connected.  (recheck, and look for a "K" or an "M" on your meter to indicate thousands or millions of Ohms)

There's supposed to be a jumper from 12 to 14.  I don't see it in your photo.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline dawnchorus

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Reply #2 on: September 01, 2016, 03:11:37 PM
Terminals 2 and 4 are connected by a piece of wire.  If the piece of wire is there and well soldered, they cannot have a different resistance reading.  If they do indeed have such a wildly different resistance reading, then the piece of wire is not well connected.  (recheck, and look for a "K" or an "M" on your meter to indicate thousands or millions of Ohms)

There's supposed to be a jumper from 12 to 14.  I don't see it in your photo.

Thanks for your reply, I checked Terminals 2 and 4 again and they did end up having the same resistance reading. My meter is not very consistent so they fluctuate between 0.2K and 0.3K ohms. The jumper from 12 to 14 is there, the photo is a little deceiving and it looks like its part of the one above it. See the annotated photo below.

I also read the stickied thread "Crack Grounding, Tracing The Signal and Power Supply Common/Ground" and all of the measurements from that are fine up until terminal 12-14.

I resoldered pretty much every joint and rechecked every step of the manual a few times so at this point I'm pretty confused as to what the issue could be. What is so strange is that last night all of the resistance measurements were fine and I haven't touched it until this morning and they were all over the place again.



Offline dawnchorus

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Reply #3 on: September 01, 2016, 04:31:28 PM
Okay so I got all the terminals besides the right RCA ground solved by completely taking apart terminals 14 and 20 and reattaching and resoldering all of the components.

The right RCA ground still doesn't show a reading though. Any ideas? I'm so close!



Offline dawnchorus

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Reply #4 on: September 01, 2016, 05:21:23 PM
Solved RCA ground issue by tightening the nut.