Colleagues: We have a problem with one of our Thermo LTQ Orbitrap XL
instruments. If you have time I have listed below all that we know and have
done to try to correct the problem.
1. Long ago when the trap was scanned an error cropped up in which the
readbacks on the Tune page for the +28v, +36V and 150v power supplies were
marked with a red cross and the voltages were way low. This problem only
occurred when then trap was scanned. It never occurred when we collected MS2
data scanning the trap, and hundreds of runs were completed successfully in the
MS2 mode. The problem never occurred when the FT was scanned. And if the trap
was scanned the problem came and disappeared during a run. We used the
instrument in this state for a long time as it was mostly used in the IT MS2
mode.
2. One day I noticed that the FT Penning gauge suddenly went from reading
about 1 x 10^-10 to 0.03 x 10^-10. It stayed at that reading for some time and
the instrument so far as we are aware worked as before. We continued to use it
in the IT MS2 mode.
3. Then one Monday morning I discovered the instrument had shut off. None of
the pumps were on. I turned the instrument back on and it pumped down OK, but
the FT Penning gauge read 0.00 x 10-^-10. The instrument ran for a few days
and I ran some samples. Then it shut down again. The main turbo speed was
zero.
4. We swapped the main turbo controller from another instrument. Same
results. It pumped down OK, ran for a few days with the FT Penning gauge
reading 0.00 x 10^-10, then the main turbo quit again. All the pumps shut off.
5. We swapped the big front-end turbo from another instrument. Same results.
It pumped down OK, ran for a few days with the FT Penning gauge reading 0.00 x
10^-10, then the main turbo quit again. All the pumps shut off.
6,. We swapped the FT Penning gauge from another instrument. Same results.
It pumped down OK, ran for a few days with the FT Penning gauge reading 0.00 x
10^-10, then the main turbo quit again. All the pumps shut off.
7. We swapped the Power Distribution Boards from another instrument. Same
results. It pumped down OK, ran for a few days with the FT Penning gauge
reading 0.00 x 10^-10, then the main turbo quit again. All the pumps shut off.
We donβt know what is wrong. When the main turbo quits all the pumps quit.
We have an almost identical instrument that we can use to swap parts. Any
advice that can help us solve this problem will be greatly appreciated.
Kym
Kym Francis Faull, Ph.D.
Director, Pasarow Mass Spectrometry Laboratory
Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA
Professor Emeritus on Recall, Department of Psychiatry and Biobehavioral
Sciences
David Geffen School of Medicine at UCLA
Telephone: (310) 206 7881 (office)
Telephone: (310) 206 7886 (laboratory)
Facsimile: (310) 206 2161
Electronic mail: <email obscured> <email obscured>>
I think you have overlapping symptoms that might be disconnected from each
other.
penning gauges in my hands have about a ~10 year life. so, a failed read
is probably not a concern other than diagnosing poor signals from the orbi.
The ltq-fts used to have a failsafe shutdown based on vacuum readings, but,
I think that was based on the reading in the LTQ. there was a jumper
switch that was able to turn that off. I am not sure if the orbis have the
same failsafe or mechanism to turn that off.
So, I aside from your issue of doing MS1 in the LTQ, I am wondering if the
ion gauge in the LTQ is bad or if the reading is bad in an intermittant
fashion. which (on the LTQ FT) would trigger a 15' countdown then a
failsafe shutdown.
if you were doing an acquisition during the time when the shutdown
occurred you would be able to use the proteowizard tool kit to access the
instrument readbacks from the data file. I would plot the vacuum readings
over time and see if one changed ~15min before the shutdown occurred.
Rest of post
On Thu, Dec 9, 2021 at 8:21 AM Kym Faull <email obscured>> wrote:
> Colleagues: We have a problem with one of our Thermo LTQ Orbitrap XL
> instruments. If you have time I have listed below all that we know and
> have done to try to correct the problem.
>
> 1. Long ago when the trap was scanned an error cropped up in which the
> readbacks on the Tune page for the +28v, +36V and 150v power supplies were
> marked with a red cross and the voltages were way low. This problem only
> occurred when then trap was scanned. It never occurred when we collected
> MS2 data scanning the trap, and hundreds of runs were completed
> successfully in the MS2 mode. The problem never occurred when the FT was
> scanned. And if the trap was scanned the problem came and disappeared
> during a run. We used the instrument in this state for a long time as it
> was mostly used in the IT MS2 mode.
>
> 2. One day I noticed that the FT Penning gauge suddenly went from reading
> about 1 x 10^-10 to 0.03 x 10^-10. It stayed at that reading for some time
> and the instrument so far as we are aware worked as before. We continued
> to use it in the IT MS2 mode.
>
> 3. Then one Monday morning I discovered the instrument had shut off.
> None of the pumps were on. I turned the instrument back on and it pumped
> down OK, but the FT Penning gauge read 0.00 x 10-^-10. The instrument ran
> for a few days and I ran some samples. Then it shut down again. The main
> turbo speed was zero.
>
> 4. We swapped the main turbo controller from another instrument. Same
> results. It pumped down OK, ran for a few days with the FT Penning gauge
> reading 0.00 x 10^-10, then the main turbo quit again. All the pumps shut
> off.
>
> 5. We swapped the big front-end turbo from another instrument. Same
> results. It pumped down OK, ran for a few days with the FT Penning gauge
> reading 0.00 x 10^-10, then the main turbo quit again. All the pumps shut
> off.
>
> 6,. We swapped the FT Penning gauge from another instrument. Same
> results. It pumped down OK, ran for a few days with the FT Penning gauge
> reading 0.00 x 10^-10, then the main turbo quit again. All the pumps shut
> off.
>
> 7. We swapped the Power Distribution Boards from another instrument.
> Same results. It pumped down OK, ran for a few days with the FT Penning
> gauge reading 0.00 x 10^-10, then the main turbo quit again. All the pumps
> shut off.
>
> We donβt know what is wrong. When the main turbo quits all the pumps
> quit. We have an almost identical instrument that we can use to swap
> parts. Any advice that can help us solve this problem will be greatly
> appreciated.
>
> Kym
>
>
> Kym Francis Faull, Ph.D.
> Director, Pasarow Mass Spectrometry Laboratory
> Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA
> Professor Emeritus on Recall, Department of Psychiatry and Biobehavioral
> Sciences
> David Geffen School of Medicine at UCLA
> Telephone: (310) 206 7881 (office)
> Telephone: (310) 206 7886 (laboratory)
> Facsimile: (310) 206 2161
> Electronic mail: <email obscured> <email obscured>>
>
>
>
>
>
>
>
>
>
> ββ
> View topic http://list.abrf.org/r/topic/1PqCzd8kWhmaxqYf0qV8hn
> Leave group <email obscured>?Subject=Unsubscribe
>
>