Chromatography Forum

I really need your help about a problem we have with a Thermoquest GCQ Mass Spectrometer System. There seems to be a problem probably with the diffusion pump and the following message appears when we open the Tune window: There is not sufficient vacuum to turn the RF subsystem. The foreline pressure is approximately 40 mtorr. The diffusion pump is definately cold.
We tried to fix the problem by changing the fuse on the diffusion pump control PCB. When we turned on the MS after a few minutes the green led on GCQ Plus front panel turned on indicating that the vacuum was ok. When I tried to open the Tune window the green and blue Leds on machine's front panel began alternating flashing and the message not having sufficient vacuum appeared on the screen. After a few minutes a fuse probably the new made an explosive sound and a sparkle. My colleagues say it is probably is the diffusion pump heater. Does anybody has a clue about this problem? Thank you!

I think that your best move will be to get a service engineer to look at it - clearly there is a serious problem, with the potential to do further damage if you try in-house fixes.

Peter

Thank you for your answer and your time! I think that is the best thing to do. I just needed to have a clue where the problem comes from. For example if a damaged heater can cause all this as I 've been told.