Troubleshooting -- LEDs Don't Light [resolved]

baby-alligators · 3281

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Offline baby-alligators

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on: August 08, 2016, 04:11:28 PM
Hi,

I have a problem with the LEDs in the chassis of the Bottlehead Crack. All of the resistance checks seem to be okay (with a little weirdness on 13, but googling returned results saying it was probably okay). When I plug it in, the LEDs inside do not light up. Both silver banded sides are facing in, and they are both new after having to order replacements.

Resistance checks are as follows:

Expected Actual

1  *
2  *
3  0 ohms 
4  *
5  *
6  2.4K ohms
7  2.9K ohms
8  0 ohms
9  2.4K ohms
10  2.9K ohms 
12  0 ohms
13  *will climb slowly towards 270K ohms
14  0 ohms
20  0 ohms
22  0 ohms

B3  2.9K ohms
B6  2.9 Kohms

RCA jacks:
Ground lug  0 ohms
Center pin  90-100Kohms


1  *
2  *
3  0
4  *
5  *
6  2.48K ohms
7  2.94K ohms
8  0
9  2.96K ohms
10  2.48K ohms
12  0
13  *drops from around 11-17M ohms or sometimes reads 0 ohms
14  0
20  0
22  0 *sometimes 0.1-0.4 ohms

B3  2.94
B6  2.96

RCA jacks:
Ground lug  0
Center pin  96.3, 99.3K ohms


Any help would be much appreciated. I can take pictures of any parts if that would be helpful.

Thank you for reading.
« Last Edit: August 24, 2016, 05:53:18 AM by Caucasian Blackplate »



Offline Paul Birkeland

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Reply #1 on: August 12, 2016, 12:12:58 PM
Can you post any voltages in your Crack that aren't consistent with what's listed in the manual?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline baby-alligators

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Reply #2 on: August 13, 2016, 12:58:25 PM
Can you post any voltages in your Crack that aren't consistent with what's listed in the manual?

1: -.721
2: -.716

4: -.715
5: -.725

7: 4 mV

9: 5.2 mV

13: -.716
14: -233
15: -.705

20: -233
21: -.710

A1: -.723

A6: -.714

B1: -.720
B2: -.716
B3: 4 mV
B4: -.723
B5: -.715
B6: 5 mV
B7: .2 mV

That's all of the ones that are different than the listed voltages. Doesn't seem particularly "good." Thanks for the response and your help.



Offline Doc B.

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Reply #3 on: August 13, 2016, 03:52:39 PM
Do you have a fuse in the fuse holder?

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


Offline baby-alligators

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Reply #4 on: August 17, 2016, 10:13:39 AM
Do you have a fuse in the fuse holder?

Sorry for the delayed response, I was out of town and unable to confirm. Fuse has been in in the fuse holder during all testing, yes.



Offline Doc B.

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Reply #5 on: August 17, 2016, 10:29:13 AM
Are you sure that your power switch is not melted in such a way that the contacts aren't closing when switched on? The more or less all zero voltages are consistent with the power transformer not getting any juice. Do the tubes glow when you switch it on?

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


Offline baby-alligators

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Reply #6 on: August 18, 2016, 10:03:15 AM
Are you sure that your power switch is not melted in such a way that the contacts aren't closing when switched on? The more or less all zero voltages are consistent with the power transformer not getting any juice. Do the tubes glow when you switch it on?

The power switch does not seem to be melted in any way. I can get pictures of any part though if you want them.

Both tubes glow when it is powered on.



Offline Doc B.

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Reply #7 on: August 18, 2016, 10:43:45 AM
Are you sure your meter is set properly and well connected to ground?

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


Offline baby-alligators

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Reply #8 on: August 18, 2016, 04:19:58 PM
Are you sure your meter is set properly and well connected to ground?

I'm pretty confident. I've been clipping the black lead to terminal 12.

Here's a picture of the meter and setting I've been using to test.
(https://i.imgur.com/g0FGZXK.jpg)



Offline fullheadofnothing

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Reply #9 on: August 18, 2016, 05:45:56 PM
Post pictures of your build, especially the power supply.

Joshua Harris

I Write the Manuals That Make The Whole World Sing
Kit Packer Emeritus


Offline baby-alligators

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Reply #10 on: August 19, 2016, 10:14:11 AM
Post pictures of your build, especially the power supply.

Here's (https://imgur.com/a/4dVI5) an album with photos. Let me know if you need any pictures of other areas.



Offline fullheadofnothing

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Reply #11 on: August 19, 2016, 10:53:34 AM
You are missing the wire connecting 12 to 14.

There are some other sketchy looking connections (the leads of the UF4007s on the transformer side are dangerously close to touching, some of your solder connections look like a wire poking through a blob of solder with no actual connection, the 9-pin looks problematic, but the shots of it are unclear).

Joshua Harris

I Write the Manuals That Make The Whole World Sing
Kit Packer Emeritus


Offline Deluk

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Reply #12 on: August 20, 2016, 01:43:12 AM
Very brave not numbering up the chassis plate.



Offline baby-alligators

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Reply #13 on: August 20, 2016, 06:46:41 AM
You are missing the wire connecting 12 to 14.

There are some other sketchy looking connections (the leads of the UF4007s on the transformer side are dangerously close to touching, some of your solder connections look like a wire poking through a blob of solder with no actual connection, the 9-pin looks problematic, but the shots of it are unclear).

Ahhhh I'll check all those areas more closely and get that wire in. Thanks for taking a look. I think I forgot to reattach that wire when I was redoing some parts (back when I was troubleshooting not noticing the LEDs being the wrong way).

I appreciate you taking the time to respond!

Very brave not numbering up the chassis plate.

Printed out the numbered page to have next to the build, but I definitely regretted not doing that a few times!



Offline baby-alligators

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Reply #14 on: August 29, 2016, 03:13:22 PM
You are missing the wire connecting 12 to 14.

There are some other sketchy looking connections (the leads of the UF4007s on the transformer side are dangerously close to touching, some of your solder connections look like a wire poking through a blob of solder with no actual connection, the 9-pin looks problematic, but the shots of it are unclear).

I did one check over the connections and added the wire, and got the LED going from the center of the 9-pin to A3 to light. The A8 LED is still not lighting.

While running voltage checks, I blew the fuse by accidentally short circuiting with the multimeter probe, so my troubleshooting has come to a stop until I get a new fuse.