That oscilloscope ground clip trick nobody talks about...

I was chasing a phantom glitch in a Garmin GNS 430 for three days straight. Checked all the pins, reflowed solder joints, even swapped the whole unit out. Turned out my cheap oscilloscope ground clip was picking up noise from the shop lights. I clipped the ground wire direct to the airframe ground instead of the test bench lug and the waveform cleaned up instantly. Saved me from sending a good unit back to the shop for no reason. Has anyone else had a bad ground clip mess with their readings?

3 comments

3 Comments

xena125d ago

Had a buddy who spent a week troubleshooting an engine monitor before realizing his scope ground was picking up the soldering iron in the next bay.

josephbutler25d ago

Man I read a thing not too long ago about how workshop environments are just full of electrical noise, especially from those cheap amazon soldering stations. It makes total sense that the scope was picking that up, those grounds can act like an antenna for all kinds of garbage. Your buddy must have felt pretty dumb when he figured it out, but honestly I bet half the guys on here have made a similar mistake with gear interactions. It's one of those things you just have to learn the hard way, I guess.

owens.cameron15d ago

Damn, that's rough but I gotta ask... what kind of engine monitor was it? Was it one of those fancy digital displays or one of the older analog ones with the needle gauges? I'm just trying to picture how deep he had to dig before he caught on to the soldering iron noise. Like, did he try swapping out the whole monitor first or was he tearing into the wiring harness?