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.