7
Diagnostics and Troubleshooting
Troubleshooting
138
TSQ Quantum XLS and TSQ Quantum GC User Guide
Thermo Scientific
Issue:
Transfer
line overheats.
Possible cause/solution
• The transfer line temperature sensor is defective. Replace the transfer line.
High Vacuum Issues
High vacuum problems can manifest themselves in two ways:
• An intermittent vacuum condition (the vacuum pressure in the vacuum manifold
fluctuates intermittently) can cause chromatographic signals to drop out, or, if the
pressures exceed the maximum allowed pressures set in Xcalibur (See
),
then the TSQ Quantum XLS or TSQ Quantum GC turns off.
• If the vacuum is consistent enough that it does not exceed the maximum allowed pressure
and avoids the Xcalibur automatic shutdown, non-reproducible false chromatographic
peaks can be generated in the chromatogram.
Typical forepressure readbacks are 30 to 40 mTorr (in EI mode), and typical manifold
pressure (ion gauge readback) is 2
×
10
-5
Torr with argon collision gas on, and 2
×
10
-6
Torr
with Ar collision gas off.
The most reliable way to find vacuum leaks is to spray a gas around the vacuum manifold and
look for the characteristics ions in full-scan EI mode. Argon produces
m/z
40. Alternatively,
you can use compressed electronic dusting spray containing an HFC. For example, Falcon
®
Dust-Off
®
and MicroCare
®
Micro-Blast
™
contain tetrafluoroethane, which produces ions at
m/z
69 and 83.
Issue:
Forepump will
not turn on.
Possible causes/solutions
• The forepump is off. Check the forepump switch.
• The vacuum service switch is in the Off position. Place the vacuum service switch in the
operating position.
• The forepump power cable from the TSQ Quantum XLS or TSQ Quantum GC
is not
connected. Connect the power cable.
• The forepump is faulty. Replace the forepump.
Issue:
Forepump
powers on, but will not
pump down.
Possible causes/solutions
• The oil level in the forepump is insufficient. Check oil level; add oil if necessary.
• The foreline is leaking. Check the clamps and connectors. Replace the foreline hose if a
hole is found.
• The vacuum manifold cover is leaking.
• The forepump is faulty. Replace the forepump.