Trouble shoot new build, no sound.

[scotheath]

I just finished a les luis build I took my time doing over the last couple weeks, forgot to check before boxing it though. I could play through it but once turned on lost sound. Unboxed it and used test prob with iPod and my test box, it has an in and an out along with 4 alligator clips. In, Out, Hot and a Ground, I've used many times before to test before boxing but forgot this time,ugh. Ran the probe through the entire circuit and have a clear signal coming through on the out of the PCB. Plugged guitar in and nothing. Plugged iPOD back into the in and played around with it. Found a few things that I've never run into before while doing this.
Only have sound when volume pot is turned all the way off, move it up slightly and sound lost. removed pot and checked it, its good.
Music coming through is not clear, that might be normal I'm not sure.
Started wiggling wires around and the ground clip from test box to ground from PCB came off and had a huge increase in volume, that seems like it might be something but I don't know enough to know what.
I went through all solder connections and re heated them. All else looks good. Does anybody have any ideas??

[jimilee]

Sounds like you're on the right track. Can you post some clear closeup pictures of both sides and your off board wiring. I think you're on the brink with this one.


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[scotheath]

I've removed from box and am just using test box to test. R8 was a jumper that I clipped. I've never used 1 before and was 2nd guessing it, made no difference.

[jimilee]

And your off board wiring, how does that look? Jumpers are important if they are in the sound path.


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[scotheath]

Not sure what you mean by off board? its outa the box I'm using this test box set up.
I clipped the jumper while trouble shooting has not changed anything, that I can tell

[jimilee]

Not sure what you mean by off board? its outa the box I'm using this test box set up.
I clipped the jumper while trouble shooting has not changed anything, that I can tell

Gotcha, I didn't realize the stomp was not connected also. My bad. The cap values look right, have you checked the resistor values? D2 and D4 need, the solder needs to flow through the holes. those two look a little starved.

[scotheath]

Yeah, I checked all the resistors, values are correct, for plan I was following anyways. I have been looking at other schematics of the les luis and some of the values are different, but I'm having a tough time with the no sound at all with audio prob if volume pot is off zero and why with the audio prob I get a good signal coming from the PCB out wire and all throughout the board. I will put some more solder to D2 and 4. I've always found something with the audio prob on previous fails, a solder bridge or loose connection where signal stops but this has got me pretty frustrated.

[scotheath]

Another odd thing is how I can get a signal with ipod running through it into amp but absolutely nothing with a guitar going through it

[jimilee]

Another odd thing is how I can get a signal with ipod running through it into amp but absolutely nothing with a guitar going through it

Yep, that is strange. I couldn't find a schematic for this one either. I'm assuming you've tried a different guitar cable I'd an iPod works just fine?


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[scotheath]

No Its not the cable or the guitar. Got me stumped though.

[scotheath]

Yeah the iPod works just fine, volume control works to increase volume. Has me really stumped. Just went through it again. Used probe again to trace through schematic. I found a Madbean LaVache schematic that uses same values for all components except madbeans has a 500k gain pot where this project uses a 1k pot, other than that they are identical so I used that to trace with probe, only place I lose volume is through the diodes but at the out on the PCB I have good volume with iPOD running through it. With Guitar notta !! WTF