Heterodyne Mini Ain't Working

[diafebus]

Hey there! My first SMD build, after many, many, many pedals, more than 20 so I would say it's a new thing but I'm not a beginner in soldering, but of course it wouldn't work right out of the Iron.

I measured with the tester and after the diode, it bridges the + to the ground, my question is, with visual inspection I don't see any legs being bridged or anything, how would you troubleshoot this guy and find what's causing the ground issue? I don't have a heatgun to remove SMD ICs, it's gonna be a pain in the ass to have to remove them one by one until I find Which IC is the problem, but what if it's not an IC?




I also added a volume pot, 100k at the output of the PCB because I read complaints of this pedal beeing too loud on its own, so there you go.

Thank you!

 

[Stickman393]

To confirm here: you have a direct short to ground after the cathode of D1, yeah? Close to 0 ohms?

If so, that'll narrow it down significantly. At that point you have four components that could be the culprit.

Those would be the cathode of D1, the positive side of c15, r11, or r100.

If you have like 2-10ish ohms to ground on the cathode of D1, then I'd test on the opposite side of r11. See if that yeilds a measurement closer to 0. If that's the case, then there's lots of other components to check.

 

[diafebus]

To confirm here: you have a direct short to ground after the cathode of D1, yeah? Close to 0 ohms?

If so, that'll narrow it down significantly. At that point you have four components that could be the culprit.

Those would be the cathode of D1, the positive side of c15, r11, or r100.

If you have like 2-10ish ohms to ground on the cathode of D1, then I'd test on the opposite side of r11. See if that yeilds a measurement closer to 0. If that's the case, then there's lots of other components to check.

hmm its a short of about 0.15 ohm, yes after D1 would be the cathode. Between D1 cathode and Ground. I measured and yes, after R11, it measures 10ohm to ground, so that part shouldn't be affected by the short, R100 also looks to be good in working condition, so I'm left with C15, which I'll have to remove the board from the pedal and lift to see if its him failing or maybe a false connection under the board ^^

 

[Stickman393]

Cool, that makes our scope here pretty narrow.

I'd be looking for solder bridges first. That will be your most likely scenario. Those can be exceedingly thin, barely visible to the naked eye. Honestly, it wouldn't hurt to hit all those connections I spoke of before with a soldering iron, and to slide the hot soldering iron between those and adjacent terminals.

A shorted capacitor isn't impossible, but it is *very* unlikely. I've never run across a brand new cap that was shorted.