Agilent 1100 LC-MSD pump down problem

Discussions about GC-MS, LC-MS, LC-FTIR, and other "coupled" analytical techniques.

5 posts Page 1 of 1
Hi,

I'm having an issue getting an Agilent 1100 LC-MS (G1946D) system to pump down. When first turning on the instrument, the rough pump turns on, and the rough vacuum very quickly drops to < 3 torr. Turbo 1 will ramp up and approach 100%, then turbo 2 will show some power but remain at 0%, then turbo 1 will immediately shut off. The high vacuum gauge never turns on and the pump down never completes (no error message, the pump down window just stays up). I did at some point get an error message (not sure how/when) that said "Turbo pump#2 showed power but no speed after turn on". The only other thing that seems potentially problematic is that the MSD electronics page shows "low" for the +28V value.

Does this seem like a turbo pump problem and/or a power supply problem? I have limited funding, so if it's a matter of swapping out a part I'd rather do that than calling in service...

Thanks for any help.

-SH
It could be a turbo pump problem. I can't remember where turbo 2 is on a 1946MSD. If it's somewhere where you can get to the top of it, you might be able to see its rotor through the protective grid (the question is whether it's buried under a load of ion-optics; I can't remember). If you can see it, you can try blowing air on it gently to see if it turns round. If it doesn't, its bearings might have seized. I'm afraid if your budget is tight, turbo problems are not cheap.
Not familiar with this instrument but have worked with turbo pumps for a long time. What was mentioned above it the best way to check one and it doesn't take much air flow at all to make one spin if it has good bearings. If the pump is bad, do a search online as there are companies that refurbish these at half the cost of new ones, and maybe even less. Some work on an exchange where you send them your old one and they send you a refurbed one so the turn around is quicker.

If it isn't the pump then you have to look at the controller and the power supply, either of which could be bad. The power supply for the MS is probably less expensive than the turbo pump controller.
The past is there to guide us into the future, not to dwell in.
Thanks for the replies. I'll try to test out the pump rotor today. I've found options online for all three parts at affordable prices, so replacing should be feasible if needed.
hopefully you were able to source the parts needed to repair the vacuum system on your 1100 LCMS.
I was trained on the original HP G1946A back in 1998 and still support 20 plus systems in the UK. Most continue perform as good as when they were installed.

To share with the community the following observations when working with the G1946/56.
28 volts is only activated once both turbo pumps are up to speed and the hivac gauge is on.
The Edwards turbo controller has one green and 3 red LED to show the activity of the pump as it spins up.
air can be used to observe if turbo is able to rotate. Check first that no oil or moisture are present. alternatively a GC syringe needle can be gently inserted through the splinter shield to carefully check if the turbo rotor is free to spin.
5 posts Page 1 of 1

Who is online

In total there is 1 user online :: 0 registered, 0 hidden and 1 guest (based on users active over the past 5 minutes)
Most users ever online was 1117 on Mon Jan 31, 2022 2:50 pm

Users browsing this forum: No registered users and 1 guest

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry