Hi All,
Question for people. I'm trying to use one of these ancient knockoff Saleae's (actually labeled as a usbee ax pro) to look at an SMTPE signal, but I'm not triggering at all. I hooked up my scope, and I noticed there's a 3V DC offset that goes away when I unhook the LA.
First I found that my previous USB cable didn't have continuity between the shell at both ends, but then I switched to another cable that did, and it STILL had the offset. Looking at the circuit, I noticed the resistor and cap that tie the LA's GND to the USB GND were also missing, so I added a 100R resistor. Same result still.
I can literally see the offset if I hook a DMM between any of the channels and gnd on the analyzer.
Has anyone else seen this? Is there something I'm missing? I've checked a few channels, all have the same result.
Thanks!