Agilent MSD 5975 difficult in adjusting coils

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

3 posts Page 1 of 1

I am adjusting the coils of an Agilent 5975 MSD but cannot lower the voltages below 125 mv when working with mass 100.

Also, I am checking the test points as in the document: ... i=89978449

We leaked the foreline pump and have changed some parts, but still, I can see some oil in the pane, so I think the pump is not fully sealed.

Can somebody give me advice on the maintenance of the pump it is a Pfeiffer Duo2.5. I have all the parts for an overhaul.

I will try to reseal it. I have looked on the internet and they said that the first problem is the Vacuum so perhaps is there the problem. Also, I get 0.000 mTorr pressure in the display. It is not okay. As I have searched.

Will check the pump again. But can you give me some advice, please?

Adolfo Álvarez
Life is a game, and in a game you can win or loose, but it is still a game.
Hi Adolfo

The first step is to ensure you repair the foreline pump to allow the vacuum reading display below 200 mTorr.
Until that happens the diffusion pump will not operate and no MS parameter will be meaningful.

Years ago, when I was first bringing my 5973 back to life, I had a problem with high RF voltage. I could bring numbers into line at low mass ranges, but by the time I'd hit 500 I was out of range of what the instrument would even report(FYI at least on a 5973 running G1701BA, when you hit 2000mv the reading "rolls over" and will read a very low value).

I was diagnosed with a faulty sideboard, but that didn't fix it.

Figuring I had nothing to lose, I removed the spring contacts where the wire "cage" delivers voltage to the quads, carefully cleaned those with solvent and a swab, and reassembled. Amazingly enough, ti came right back to life.

I just mention all of this as if you've sorted all your other issues and still can't get your RF in range, try this. Failing this, it's likely an electronics issue.
3 posts Page 1 of 1

Who is online

In total there are 2 users online :: 1 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: Bing [Bot] 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