Difficulty with electron multiplier supply-5973A

[BCBC]

Any ideas would be appreciated (5973A). Will not tune and gives the error, "difficulty wih electron multiplier supply". I cleaned the HED as per Agilent. Also cleaned off the quad. contacts.
Thank you.

[willnatalie]

This boils down to a couple of issues. Do the filaments look good, or are they really dirty? Another is that the EM (unless really new) could simple be bad (unfortunitly this is like a 1200 piece). Was your EMvolts high (<2700) before this error occured. This couple lead to the filaments if they are indeed dirty. However I would say that the EM is faulty

Hope this helps.

Will Shafer

[BCBC]

Thanks for response.
The ion source is clean with new filaments. The multiplier was installed the beginning of Nov. 2009 with an initial voltage of 1047. That has remained relatively steady until Dec. 7th. when the em voltage went to 2100 and has remained there ever since. The last good tune was Jan. 06.

[willnatalie]

did you overload the detector? Can you even turn on the MSD? If not then another issue is the HED supply. This is an error that I dealt with. I could not tune as well, I had replaced and clean everything in the MSD chamber. I could not even turn it on, forget tuning.

This could mean two things.
003 Part Number
G1099-80018 73CI BIPOLAR SUPPLY $2,662.00
(my issue) A box located under the MSD chamber (a voltmeter could be used to chenck and see if there is power)

004 Part Number G1099-80001 HED Detector $1,946.00

Good luck

[BCBC]

I am not able to tune or check the profile in edit parameters. I can pump down, show the ms status, vacuum etc. Just cannot start a tune.
I'm running EI mode.
I'll update after I try a few things. I replaced the multiplier and will update when I am able to try another tune. The HED will be the next thing I look at if this doesn't solve anything.
Thank you.

[Schmitty]

Do you have another 5973 available? You could take off that whole side door and try it on another instrument if you do.

[BCBC]

I have a few parts laying around from an unused MS. There may be something useful still left on it as I've cannibalized it from time to time.

[BCBC]

Update: Multiplier change didn't solve the problem. Next step is to replace the side board.

[astroguille]

Hi!

This problem happens sometimes in my 5973, in spite of the EM is OK. But the problem is electron multiplier supply (that is tha red box on the side board). Try to clean behind this board with nitrogen: the dirty can affect the contacts. Also, you can try adjust the electron multiplier supply.

Suerte!

[BCBC]

Thanks very much for the suggestions