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May 08, 2021, 05:26:03 AM

Author Topic: LED and Voltage Issues  (Read 163 times)

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Offline pickles3201

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LED and Voltage Issues
« on: May 01, 2021, 11:19:50 PM »
Hi, so a long time ago I tried assembling a Bottlehead Crack+Speedball. I honestly don't remember if my crack pre-speedball worked or not since 1. I don't recall hearing a negligible difference and 2. there was a second LED by the 9-pin socket that I remember not knowing existed (so it probably wasn't lit?). At the time since I missed the second LED, I thought it worked and so I went along with the speedball upgrade. So here we are present day.

If you see my previous post history I posted about resistance failure checks on pins 7, 9, B3, and B6 about 2 years ago. I recently did another resistance check, and those 4 pins still read as over limit. But I actually searched it up, and I saw one post where Paul said it was fine because the Speedball changes the resistances. So are these 4 pins no longer a concern then?

And for the LEDs, a couple of the LEDs were actually on until I 'resoldered' pin A7 (voltage failure fix attempt) by adding what is probably considered too much solder, and so now no LEDs light up.
It's pretty late right now so I'll try to remove the excess solder tomorrow, but is my crack cucked or is it completely plausible that too much solder on one pin could lead to all LEDs not lighting up?

Assuming that the above problem is fixable, I did have some pictures of the LEDs before I screwed it up with the solder.
The 2 LEDs by the 9-pin socket were lit, and the 4 LEDs on the big circuit board were lit, but fairly dim in comparison to the 2 LEDs on the small circuit board. And as you can see by the image, the other 2 LEDs on the small circuit board don't light up.

In terms of voltage for the small board (before solder screw up), OA and OB were both at like 375 volts, so that's why I tried resoldering A7 (voltage was about 2 volts) but not A2 (voltage was 0). After putting a bunch of solder it's still at 375 volts. I'm definitely removing the excess, but I'm curious (assuming that removing it works) as to why too much would cause such an issue.

Any help is appreciated, thanks!
« Last Edit: May 01, 2021, 11:35:21 PM by pickles3201 »

Offline Paul Birkeland

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Re: LED and Voltage Issues
« Reply #1 on: May 02, 2021, 04:17:51 AM »
In terms of voltage for the small board (before solder screw up), OA and OB were both at like 375 volts
This tells me that your stock Crack build didn't work properly.  Are both black wires at the headphone jack captured by solder?

Can you list the voltages for:

Small board OA, OB, IB, IA.
Big board OA, OB.

I would need to see a picture of what's hooked up on your 9 pin socket, since you seem to indicate that maybe you only have one LED there.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline pickles3201

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Re: LED and Voltage Issues
« Reply #2 on: May 02, 2021, 07:46:11 PM »
I'm pretty sure both headphone jack black wires are captured by solder. Just in case, I added more. And before the weird LED non-lighting up error, I did have 2 LEDs lighting up at the 9-pin socket.

So I tried removing the solder from pin A7 but I don't have flux and the solder wick wasn't working. I'm honestly so confused as to why most LEDs were lighting up (save for a few) but then after adding solder to pin A7, none of the LEDs work. Before that happened, my voltages were basically fine. So I'm not sure what happened.

My resistance checks are fine, but the voltage checks are definitely not great. There is no voltage in pins 1-5 which probably explains why some LEDs weren't lighting. I sear I just added solder to A7 and somehow everything got screwed over. So now the previous 375 volt measurements don't really matter anymore because right now my Crack is kinda cucked.

I also have to go back to college soon, so I'm not sure how much more I can work on this unfortunately. On an unrelated note, will the repair service be available anytime soon? I'm slowly feeling discouraged from the wear of debugging haha.



Here are my current voltage measurements:

Small Board:
OA: 0
OB: 0
IB: 0
IA: 0



Big Board:
For some reason, depending on where I place my probe on the solder, it will either read 0 volts or some weird voltage. I have no idea why.
OA: 0 or 50
OB: 0 or 103



1: 0
2: 0
3: 0
4: 0
5: 0
6: 0
7: 105
8: 0
9: 47
10: 0
« Last Edit: May 02, 2021, 07:54:13 PM by pickles3201 »

Offline Thermioniclife

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Re: LED and Voltage Issues
« Reply #3 on: May 02, 2021, 08:32:02 PM »
It appears that one led on the A socket is miswired. It should be connected between pin A3 and the center terminal. It seems to look like it is connected to pin A1 and pin A2 or A3, It is hard to tell because the wiring is obscuring the connections.
Lee R.

Offline pickles3201

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Re: LED and Voltage Issues
« Reply #4 on: May 02, 2021, 08:36:31 PM »
Yeah sorry for the bad photo. It was mostly just to show that I had both of them there, but the angle is definitely pretty bad. One LED is going from A3 to center, and the other LED is going from A8 to center.

Offline Paul Birkeland

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Re: LED and Voltage Issues
« Reply #5 on: May 03, 2021, 05:34:24 AM »
You had 375V initially, now you have 0V.  Either you have a blown fuse or a very, very loose connection.

The presence of the 375V in your measurements tells me there's a loose connection in your amp and it's absolutely critical that you stop focusing on the LEDs themselves and reflow the solder joints in the rest of the amp.  You don't get voltages that are higher than what's supposed to be in the kit unless you have a loose solder joint or you miswire the power transformer (which will cause the power supply caps to fail immedaitely).

So you have solder joint issues, 100%.  Without first resolving these issues and seeing 170-200V on the IA/IB terminals on the small PC board (which is connected to B2/B5, as well as terminals 2 and 4), your LEDs won't light. Your LEDs can also not light up if the tubes aren't glowing, and that's another common issue that has nothing to do with the LEDs themselves.

If you resolder the LEDs themselves too much, they will melt and need to be replaced.  But again, don't focus on the LEDs, you have other issues elsewhere. 

Do you still have the 22.1K and 3K resistors?  Removing the Speedball and putting the amp back to stock could be helpful at this point.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man