Troubleshooting
Troubleshooting Guides
Thermo Fisher Scientific
Model 42
i
Trace Level Instruction Manual
6-3
Malfunction
Possible Cause
Action
Excessive Noise
Defective or low sensitivity
PMT
Unplug power cord. Remove
PMT. Install known good PMT.
Plug in power cord. Check
performance.
Defective input board
Replace board.
Defective cooler
Check temperature (less than -
2 °C at T
amb
= 25 °C).
Non-linear response
Incorrect calibration source
Verify accuracy of multipoint
calibration source gas.
Leak in sample probe line
Check for variable dilution.
Excessive response
time
Partially blocked sample
capillary
Unplug power cord. Clean or
replace capillary.
Hang up/blockage in sample
filter
Change element.
Improper converter
operation
Questionable calibration gas
Verify accuracy.
Converter temperature too high
or too low
Temperature should be
approximately 325 °C.
Low line voltage
Check to see if line voltage is
within specifications.
Molybdenum consumed
Replace Molybdenum converter
cartridge.