7200B QTOF does not turn on TOF Vac

Question

Hi!

We recently vented our system in order to change the column. However, now the system does not turn on the TOF vac. Rough pump and quad. are at normal levels, all turbopumps at 100% speed. But TOF just says "Off". We've tried to powercycle the instrument and rebooted the computer to no help.

Any ideas?

Thanks!

paulsalverda · Answer

The TOF vacuum gauge looks like this: It is mounted on the TOF manifold below the flight tube and is visible looking behind the GC. Make sure the cable is still connected. I know, I know, but have to ask anyway. There is an LED on it -- if it's red, either the gauge is bad - there's a filament inside, or it needs to be reset. Typically the reset happens when you power cycle the MS. Set it to vent, but don't let it get all the way vented, and set it to pumpdown again.