HED Supply Difficulty

[espx_2]

Hi there!

Good day to everyone.

We have an Agilent GC-MS 5975c, 2 years of age, and has recently gone for a preventive maintenance a month ago. Apparently, we cannot operate it yet due to various problems we have encountered. After the MSD is back in its place and everything was observed when we have re-started-up, pump down the system and baking the MSD for 24 hours, still we cannot perform even Autotune (and any kind of tuning) because the filament goes on and off during tunes.

We got these errors when we conducted Tune Evaluation and actions we've taken to troubleshoot the MSD:

1. No PFTBA in calibration vial. (We just restored its content during the maintenance).
2. Large Air Leak (we tried to blow-off Argon gas and acetone on the seals; no peak detected on m/z's 40 and 58, respectively).
3. Restore previous good Autotune files (Still no avail).
4. Tried to capping the MSD interface with a no-hole ferrule and blow-off Argon gas (no leaks found also).
5. Re-cleaned the Ion Source and the HED, still problem is unsolved.
6. Checked out the turbo pump and the foreline pump, still ok. (although we don't have ion gauge to justify the pressure inside the MSD, our basis was the Vacuum Status report only).
7. We also replaced the electronic boards to find out if this causing the problem, apparently all our circuit boards were working fine because the same results we got even if we replace it with a new one.

By the way, this problem was very odd to the guys we hired to render the maintenance service on our equipment who has 20 years plus experience in GC-MS.

I hope anyone out there could try lend us a hand on this matter.

Thanks,

[kubowicz.tomasz]

Hello

I'd try:
1.Open MSD config file, remove MSD from configuration and configure it again.
2.Change filament in tune mode to filament 2, then save it and try to run autotune with Fil2.

Regards

Tomasz Kubowicz

[Peter Apps]

If you cannot tune then you cannot leak check by spraying argon or acetone and then looking for specific single ions because the fragment masses might not be accurately measured. Try the leak check again but monitor a range of ions centered on the expected fragment masses.

Peter

[espx_2]

If you cannot tune then you cannot leak check by spraying argon or acetone and then looking for specific single ions because the fragment masses might not be accurately measured. Try the leak check again but monitor a range of ions centered on the expected fragment masses.

Peter

Hi Peter,

We can do manual tuning on the assigned mass number but it is interrupted shortly by an error which the filament goes off. Sure I'll try to do what you have said.

Thanks,

[espx_2]

Hello

I'd try:
1.Open MSD config file, remove MSD from configuration and configure it again.
2.Change filament in tune mode to filament 2, then save it and try to run autotune with Fil2.

Regards

Tomasz Kubowicz

Hi Tomasz,

We've already tried the shifting to the other filament but still without avail. We'll try to reconfigure the MSD configuration file.

Thanks,

[espx_2]

Hi everyone!

Still not working well. Any suggestions?

I tried everything on the book, I guess... I also got this error message: "Tune action stopped: Undefined Symbol: v" What does this mean?

Thanks,

[01310040231]

Are you sure your turbopump is ON while the system is being tuned?

[James_Ball]

I would have thought on the 5975s the ion gauge tube was standard equipment, but maybe not. On the 5975s they do not have a separate gauge controller like what was on the 5973, instead the gauge readout is in the software and appears normally in the tune window and in the vacuum status window. If you have the squarish part with wires sticking out of the back of the vacuum chamber then you have the ion gauge, if you have it check in tune and see what the vacuum is when in manual tune, hopefully with the inlet blocked off it will be in the low -6 torr range. If not then there is a vacuum problem, which this does sound like.

Also if you tell the instrument that you have the CI source installed, it will give you a higher cutoff on analyzer pressure so that you might be able to see is there is a large but not massive leak. It would allow you to scan with higher analyzer pressure, but still cut off the filaments if it is a massive leak.

[espx_2]

Are you sure your turbopump is ON while the system is being tuned?

Yes, turbopump and foreline pump were on.

[espx_2]

I would have thought on the 5975s the ion gauge tube was standard equipment, but maybe not. On the 5975s they do not have a separate gauge controller like what was on the 5973, instead the gauge readout is in the software and appears normally in the tune window and in the vacuum status window. If you have the squarish part with wires sticking out of the back of the vacuum chamber then you have the ion gauge, if you have it check in tune and see what the vacuum is when in manual tune, hopefully with the inlet blocked off it will be in the low -6 torr range. If not then there is a vacuum problem, which this does sound like.

Also if you tell the instrument that you have the CI source installed, it will give you a higher cutoff on analyzer pressure so that you might be able to see is there is a large but not massive leak. It would allow you to scan with higher analyzer pressure, but still cut off the filaments if it is a massive leak.

We're using EI for our GC-MS. The vacuum pressure reading from the manual tune (Autotune report as well) is always 0.00 x 10 E0 since we bought the equipment.

[dblux_]

.... The vacuum pressure reading from the manual tune (Autotune report as well) is always 0.00 x 10 E0 since we bought the equipment.

Turn on the vacuum gauge and you'll get vacuum value on the 5975 display and in the tune report.

[espx_2]

.... The vacuum pressure reading from the manual tune (Autotune report as well) is always 0.00 x 10 E0 since we bought the equipment.

Turn on the vacuum gauge and you'll get vacuum value on the 5975 display and in the tune report.

Apparently, although the vacuum gauge selection is present, its grayed-out. Thanks.

[dblux_]

Vacuum gauge may be not installed in your equipement. It was an option.
Or simply out of order. Check whether gauge cable is not unpluged.

[kubowicz.tomasz]

Hello

Check diodes at the back of ion gauge. It should be solid green.
If it is yellow (amber) or red ion gauge is defective.

Regards

Tomasz Kubowicz

[espx_2]

Vacuum gauge may be not installed in your equipement. It was an option.
Or simply out of order. Check whether gauge cable is not unpluged.

Actually, we don't have the ion gauge. Unfortunately, it is not within the package. I also have encountered this error as well:

"Tune action stopped: offset at maximum and the peaks are too large"

Thanks.