GC/MS

[Analisis]

Hi, well after the source was cleaned, the filaments doesn't turns on. I thought that there was not well wired and vented again to check it, but the filaments are ok. Well Somebody has some tip. What can I do?

Thanks

Adolfo

[bhuvfe]

Adolfo,

I suppose you have already tried to switch to filament 2?


I suggest you check the connections between the filament and the wire that is providing the current (i.e. is there enough grip/contact between the pin and the wire?).


Regards,
bhuvfe

[Analisis]

Hi again,

I have just vented again, checked for the work. Everything seems ok. Then pump down and checked for the filaments. OK they come on. But after a while, some half hour or so the filaments doesn't come on. What is happening. Can somebody help me.

It seems a false contact but where can I check?

Adolfo

[bhuvfe]

Check if there's enough grip between the wire and the pin. If not when you warm up your system a circuit break might be the cause of your problem.

You may try to pinch (gently) the wire with pliers to be sure to have a good contact between the pin and the wire.

[Analisis]

Hi,

Ok I would check for it. Perhaps is there a false contact, but it happens to both filaments and that is rare for me.

Well thank you for your help. I let you know.

Adolfo

[Analisis]

Hello, I want to report that after checking again for false contacts in the filaments, the problem remains the same. The filaments goes off after some time. I have tried to relate the behavior with the pressure in the system. I can observe that the filaments went out after the pressure goes bellow 5.30 e-5 torr. Well this is only a suspiction, but could also be that when the source is hotter, the filaments doesn't have good contact, but this should happen to both filaments!!!!????.

Well I understand that I should proof with other source, and with other electronic boards. Perhaps main board or the side board. The problem is that we don't have these parts and we are short of finance. So we want to try some things before calling the Agilent Service people. Somebody knows a method to find where the problem could be?

Thank you for your help.

Regards,

Adolfo Ã

[bhuvfe]

Adolfo,

It's indeed weird that both filaments go in the same moment.

To me this looks still like a circuit break. When you vent the system can you pull out easily the wires of the filaments?

If you can do this too easily at higher temperature you can have a circuit break.

The other thing I would check is the status of the connectors of these wires.
You have been cleaning/venting several times lately. Have you ever cleaned the tip of these connectors? Maybe with 100-200 microliters of dichloromethane and a syringe?

Do you see something odd on the board that gives power to the filaments?

Without having access to another board or source probably there's not a
lot more you can do.

Regards,
bhuvfe

[little_brad]

Adolfo, i suggest making a career change, perhaps McDonalds or KFC?

[krshaffe]

Adolfo,

Is it tuning...or is the filament cutting off before it gets done? Are you sure that the wires that go to the ion focus lens and the entrance lens aren't mixed up?

Brad,

Come on, Man...that was mean.

[aldehyde]

When you are checking the filaments are you actually checking for continuity using a volt meter?

[Ron]

I don't think you have much choice, you need to get a good service engineer in to take a look at this instrument. If you got oil into the vacuum chamber this will cause all sorts of problems. I suspect the oil got into an area where it has caused damage, probably by affecting electrical resistance in some of the electronics.

Little_brad, this is a forum for technical advice, not random insults.

[dhan]

we are using Inland oil 45

Very recently I got this message from Agilent

replacement part number for rough pump oil p/n 6040-0621 which is a Pfeiffer P3 pump oil. This has now changed to p/n 6020-0834 which is an Inland 45 pump oil. The reason for the change is that we changed the vacuum pumps with our newer systems, and rather than having multiple types of oil, we chose the oil that would work in all of the vacuum pumps which is the Inland 45.

affecting electrical resistance in some of the electronics

Did you check source electrical resistance "from source body to the lens". That is important (even if source is clean and good) and current is not conducting then MSD won't tune.

Dhan

[astroguille]

Try to set the RFPA

[Analisis]

Hi, It is some time since I have posted. Well the situation is OK now. The MSD is functioning ok now. The problem was a leak. It was in the column entrance of the system. Now it all functions OK.

So the problem was resolved and the solution was to tight the column. Some times after you have checked one thing you should check it again and again. The problem was that I have no additional tools, only the MSD self. I had found the leak using the manual tune and setting the parameters to search 69, 18 and 28 masses. Then I have sprayed Nitrogen in the sites where I supouse there is a leak and after some time the 28 mass grows, if there is a leak. But you should wait a time. I don't remember how much but is the time that N2 travels until reach the MSD. I have provoked the leak in the suspected part and waited until I can see the growth of the 28 mass, noting the time transcurred, then I have fixed the part and have sprayed the site with N2 and waited the time just found. When you have many junctions as my system have, it can take some time to do it. But so was the form i have found the leak and have fixed the problem.

Thank you to all that helped.

Analisis