Author Topic: I'm in a dither troubleshooting  (Read 1059 times)

TNblueshawk

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I'm in a dither troubleshooting
« on: June 22, 2013, 01:00:02 PM »
So, I'm curious what you chaps would think about this. I was having such a good run of working builds but alas time to be stumped.

So there is this OD circuit. The type doesn't matter in the context of how I would like to phrase this. You have 2 other circuits in the box too that both work thus ruling out in/out jacks as an issue. Said circuit is the first one in line. Dead as a door knob.

I'll just tell you know I swapped out the foot switch to rule it out knowing it was not it but you know.... So I draw out the audio circuit and break out the audio probe. My signal is dead on the input. However it is live on the output? How is that possible?

So, I sort of work backwards from output to input in the audio path and find the dead spot. I had to stop to take off in a minute or two before I desolder some parts. Looking at where the signal...er....starts I guess is the word I sure can't see any bad soldering.

Anyway, I can't get my mind around how my signal is dead from the input of either the jack, switch or the PCB yet I'm getting a signal on the output and about half the audio path components up to a point.

I'm sure I can't see the forest from the trees so if someone could point me to the forest that would be great  :-[
John

jkokura

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Re: I'm in a dither troubleshooting
« Reply #1 on: June 22, 2013, 02:28:36 PM »
Are you sure your output and input wires haven't been switched going from the switch to the PCB?

Jacob
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TNblueshawk

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Re: I'm in a dither troubleshooting
« Reply #2 on: June 22, 2013, 05:53:24 PM »
First thing I thought of. I found another build to see how someone else did it and I'm good on the wiring. For a second the thought of the BOM layout being wrong entered my mind too but I don't think so.

I keep thinking it is some moron move I've made but this moron can't figure it out.
John

DutchMF

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Re: I'm in a dither troubleshooting
« Reply #3 on: June 23, 2013, 02:43:29 AM »
Are you sure your output and input wires haven't been switched going from the switch to the PCB?

Jacob

Or maybe on the switch itself? Could also be one of those annoying hair-thin solder bridges on the switch?

Paul
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midwayfair

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Re: I'm in a dither troubleshooting
« Reply #4 on: June 23, 2013, 07:49:41 AM »
My signal is dead on the input. However it is live on the output? How is that possible?

Is it an op amp?

I think we need pictures and at least the name of the circuit.
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TNblueshawk

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Re: I'm in a dither troubleshooting
« Reply #5 on: June 23, 2013, 04:38:16 PM »
It is Barry's V6 so 5 trannies, trimmer for Q5. No IC's. Old etched board. It just stones me that I can touch the probe to the PCB out on the footswitch and get a signal that is controlled by the bass treb and Vol and take that probe over an inch to the input and it's dead. How is that possible!

I've been out of pocket but I may get some pics up later

No bridge Paul. This is the second footie I installed too.
John