Dear Colleagues,

We have an issue with Shimadzu QP2010SE mass spectrometer.
Lost sensitivity, at detector voltage 0,9kV hard to see any ions except 28 and 14
When increasing the voltage to 1,2-1,3kV, the ions came back but randomly goes to saturation.

Checked the power supply voltages, the high voltages, the filament etc, and seems everything is normal. Removed and checked the preamplifier (gain~30) and ok.
Lens can focus normally, peak shape could be adjusted.

The carrier gas is hydrogen.
The MS did not run a lot, still have the original filament pair and only the filament_1 is worn out (working but gives lower intensity values than filament_2)

Has anyone ever encountered a similar case?

I would be happy for any help.

I was able to make some manual tuning after changing the main rod voltage from -3,5V (default, do not adjust in normal case) to -8,5V, but double peak observed at 18.

Consulted whit the service, and cleaned the lens, the ion source, turned the pre-rod by 90° to show the clean surface to the inner side. Removed, disassembled and washed the injector assembly, and tested again.

Now the instrument is working again.

Take care when assembling the lens unit, use a plastic card (+some tape on it) as as a template (eg. used bank card) between the lenses and the frame to achieve the optical uniaxiality. This is affects the lens unit focusing performance.

There seems to have been a strong contamination in the system.