GCMS Rough Pump does not turn on but Turbo does-5973 Agilent

[iscreamsci]

Hello, I have an Agilent 6890A GC linked with a 5973 MS (both older systems --around 2000). I came in this weekend and the system had shut down. Everything came back up except for the rough pump (Edwards)...it does not come on at all. All I have been able to find from the manuals and online help is that the pumps will shut down if there is a large air leak. I've capped off the MS transfer line to eliminate a GC leak as a possibility. Still no rough pump--the turbo pump comes on fine but can't get up past 10 which I'm guessing is due to the rough pump not running. I can get into the diagnostics fine and it does recognize the MS. I was able to plug the rough pump straight into another plug oulet and it comes right on (and is creating a vacuum) so I'm thinking it has something to do with the communication between the MS and the pump. Is there any reset?? What tells the pump to turn on? I also checked the two fuses right above where the rough pump plugs into the MS and they appear to be fine. Any suggestions would be greatly appreciated. Thanks !

[MSCHemist]

The turbo will not come on fully and will shut down unless the roughing pump gets the vacuum below 300 mTorr. Can you get a read of what the foreline pressure is? Also there was a known glitch with Chemstation where the 5973 reports foreline pressure in mTorr and Chemstation thinks it is in Torr so it reads as >300mTorr and will refuse to turn on the turbo/diff pump. In order to bypass pump it down from the MS pannel without Chemstation. Otherwise sounds like a large leak and the side plate O-ring is most often the culprit. It needs an ocassion very light coat of Apiezon L grease. Wipe the O-ring off with methanol and a kim wipe, get some apiezon smeared a bit on a kim whipe and wipe it over the o-ring, then wipe the o-ring with a clean kim wipe to remove the excess.

BTW if you are getting the glitch Agilent released Chemstation MSD E02.02 SP2 (free) and that should correct the glitch.

[Consumer Products Guy]

I was able to plug the rough pump straight into another plug oulet and it comes right on (and is creating a vacuum)

OK, so sounds like the Edwards rough pump itself is OK.

I'm thinking it has something to do with the communication between the MS and the pump. Is there any reset?? What tells the pump to turn on? I also checked the two fuses right above where the rough pump plugs into the MS and they appear to be fine. Any suggestions would be greatly appreciated. Thanks !

We have a 5973 but I think that if I had the same issue I would at least talk to Agilent technical phone help at 1-800-227-9770.

I cannot recommend simply plugging the rough pump directly into a receptacle and running that way, but I'd guess that some folks have done just that.

[MSCHemist]

Sorry misread your post. The MS does not really control the rough pump. It just branches power to it so if the MSD is on then the pump should be on and vice versa. The only communication is of the foreline sensor which is part of the MSD. It is hard to say why the power supply to the roughing pump is not working unless it is too powerful a pump for it. The 5973 is not really speced for anything more powerful than an E2M1.5. You can run the pump plugged into the outlet and many people do that especially if they buy a more powerful pump like an E2M2 or greater.

In fact some folks recommend that.
http://www.cssco.com/extras/mass-spec-b ... ectrometer

[iscreamsci]

Thanks for the suggestions/help! The system had been running fine with this rough pump (1.5) since 2001 so I don't think it is too powerful. The problem looks like it is somewhere in the power supply from the MS to the rough pump.
None of this is on a service contract anymore but Agilent did say the pump could be plugged directly into an outlet temporarily which is what I am doing now until they come troubleshoot. Thanks again.

[dblux_]

You may try aldehyde's advise
viewtopic.php?f=3&t=13820&start=0&hilit=rough+pump+fuse

[James_Ball]

I have had the power board go bad in a 5973 before to where it would run everything but the rough pump. Fuses were still good, but pump would not start. We just ran it from a wall outlet without any problems, just have to remember to turn it off manually when venting and turn it back on before pump down is initiated.

If you move up to a E2M2 rough pump like many people do, you really do need to bypass the MSD power supplly when running those.

It does sound like you have either blown the fuse for the rough pump on the power board or you have lost that part of the circuit. Either way you can run it from the outlet until you can repair the board.

(an Agilent engineer ran the rough pump on our new 7000QQQ overnight when the power board was found to be defective the day after it was installed until he could install a new one the next day)

[dr_bahram1977]

Hi
you've probably faulty pump contactor. Either you can use rough pump from external power, or you've to open MSD and change contactor. it's not so hard, but not necessary too.