Shimadzu GCMS-QP2010 Series, Service Manual, Page: 65 / 168

65
Problems during tuning
8. No peaks obtained (peaks extremely small) (cont.)
Check the ion source.
□
Is the ion source correctly installed?
Check if the ion source was distorted during installation.
□
Is any foreign matter inside the ion source?
Check inside the ion source for foreign matter, such as fragments of broken column.
□
Is the column length appropriate?
Normal ionization is not possible if the column is inserted too far into the ion source.
Check the RF power supply.
□
Are the RF GAIN and RF OFFSET values appropriate?
If no peaks are obtained, reduce the RF OFFSET value to about 4000.
This reduces the resolution but makes peaks easier to detect.
□
Is the RF power supply operating normally?
See section
4.11 RF PS Assy
for details about how to check the RF power supply
operation.
Check the signal detection.
□
Does a small amount of noise appear in the peak monitor window when the
preamplifier is
tapped?
View the peak monitor at 999x zoom.
If no noise appears, check the detector wiring and the connections between the
preamplifier and CPU-A.
□
Does the baseline fluctuate in the peak monitor window when the filament turns on?
View the peak monitor at 999x zoom. If no baseline fluctuation appears, check