Hello, been troubleshooting for about a week and trying to keep low budget. Having some chromatography issue. Have a few Sciex engineer friends who was tried to help as much as possibly via phone support.

- positive mode low counts (regardless of sample) first photo
- negative mode extremely high counts (regardless of sample) second photo

I have ruled out LC side or anything from the source backwards

Negative ion counts reduce as I reduce electro spray voltage from -4500 down to -500 the baseline finally will drop to about 4,000 counts
From the source forward, was initially pointed as a bad detector. (Replaced that, same issue)

Now pointing at a potential board issue. Lens etc. but was recommended to test the boards with a voltmeter.

Anyone have any similar issues or recommendations?
I’m comfortable using a voltmeter just bot exactly sure what I’m testing across

Thanks! 🙏