Strange issues with recent builds

[ShredderNemo]

I'm finding that numerous builds of mine work excellently the first few times I use them. I box them up, and they suddenly don't work. Through fault finding, I've noticed each time it's not just a wiring/ground issue, but it's a component failing somewhere in the circuit. Is it common for components to work for a while before shorting out or dying? I'm starting to suspect some 1uf poly film caps as the suspect, as crazy as that sounds.

[Leevibe]

I find component failure to be incredibly rare. If it's happening often and with different components, I'd suspect cold solder joints.

[ShredderNemo]

Alright, so a little background information on the build I'm currently having issues with. I just finished a Madbean Wolfshirt (Foxx Tone Machine).  It was working excellently at both 9v and 18v (all components rated at 25v or higher), until I boxed it up. I traced the issue down to C13, a 1uf cap right before the volume pot. I have signal at the collector of Q4, and at the entrance to C13, but not on the other side of the cap. I replaced the capacitor with another 1uf film, and the problem persists. When I jumper the leads of the cap, I get signal, and both caps have measured just fine.

I'm not quite sure where the problem lies at this point.

[ShredderNemo]

Looks like it was 2 things: the DC jack was shorting against the case, and a ground wire not connected to the sleeve of the output jack.

[Leevibe]

Congrats on the solve! It always feels good.

[jimilee]

Looks like it was 2 things: the DC jack was shorting against the case, and a ground wire not connected to the sleeve of the output jack.

Nice job. Just an FYI for learning purposes. If you use metal 1/4" jacks and are ys by an aluminum enclosure, you don't necessarily need to ground the output jack, it grounds through the enclosure.


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