Grounding mystery

[cnspedalbuilder]

Hello, I was boxing a pedal, and as usual with these tight PCBs, it works fine until I squish it all in and then the sound cuts out. Fine, I'm going through looking for something that is shorting to ground. I might've found it, but in the meantime I ran into something that stumped me. Testing revealed that I had continuity between the input jack tip and ground, and between the PCB in and ground. This was true whether the pedal was in bypass or in active mode---even when I was able to get seemingly normal signal from the pedal. This was bizarre to me, because I'd imagine that if input is continuous with ground then you'd get the sound cutting out. Also weird is the fact that there's no continuity between the enclosure and ground--I assumed maybe that's because the enclosure has a decent amount of powder coat inside.

...anyway, I'm now more curious about this grounding thing than I am about getting the pedal boxed. I've been building this while recovering from a surgery and it's possible that my addled brain missed something. I'm sure there's an obvious issue that someone here can catch. Anyone?

[j_flanders]

Continuity on a DMM does not mean 0 Ohm. Check the manual for the 'threshold' resistance and/or measure the actual resistance between input jack tip and ground.

[cnspedalbuilder]

I'm getting a little better today health-wise and the connection between input and ground appears to have vanished... so maybe I screwed up my measurements in my sorry state yesterday. It's also possible that, when it was squished, there was a weak connection and a very low resistance b/w input and ground but enough to let some signal through. I will sort this out and only follow through if there's genuinely a mystery here. thanks.

[amptramp]

You used to be able to get a material called "fish paper" that was a grey cardboard used to keep electrical connections from shorting to ground.  It is kind of scarce now but duct tape or plastic from a blister pack can do the same thing.

[PRR]

> I had continuity between the input jack tip and ground, and between the PCB in and ground.

Guitar amps are almost always wired so, if you don't have a plug in the jack, a finger on the jack shorts the jack. This avoids the wide-open BZZZZT! when you pull the plug out.

Pedals don't always do this, but you don't say what this pedal is, so I dunno.