Chromatography Forum

Here I'm back again with my oldie Quattro Micro, which is a kinda Pandora's box for me. Since I started the instrument the work turned into infinite troubleshooting. Having solved one issue I get 1-2 instead.
Here's a new one I got stuck with:

When I increased the desolvation gas flow up to 200 L/h and more, the Capillary Voltage and Cone Voltage turned off. With lower gas flow it was OK.
I couldn't see any logical reasons except for gas quality or pressure failures.
The pressure given by generator is appropriate for QM (>6 bar).
I thought the possible moisture in nitrogen could be a reason. I opened the N2 generator, checked the filters, indeed there was some water (I think - the auto-drain failed). I cleared away off the water and let the N2 generator to pump into atmosphere within 2 days (in order to pump out the water residues if there were any).
After that the QM let me to increase desolvation gas up to 400 L/h. If higher - again the Capillary Voltage and Cone Voltage turn off.

To make things clear about gas quality, I'm gonna attach a pure N2 cylinder instead of generator.
But I'm not completely sure that it is all about moisture (because I did my best to get rid of it).
Maybe anyone dealt with such issue?

sounds like an electronic problem, I think you should contact Waters and ask them to send a field engineer to take readings at the voltages in your mass spec.

Good luck!

hello everybody again

the problem was isolated successfully, I decided to write here, probably someone else would face the similar problem

Here's the thing: there's a small switch on source enclosure and normally it is being pressed with enclosure door. When not, it turns off the capillary and cone voltage and desolvation heater. It is for safety reasons (in case one opens the source door in Operate mode).
The high flow of nitrogen happened to increase pressure in the source, so that the door was slighly pressed out with it, and the microswitch triggered.
Then I suggested that the pressure is enormously high due to imprompt exhaust. And indeed the solenoid valve integrated in exhaust line is failing.
So now I got to swap this solenoid, and this should fix the trouble definitely