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Troubleshooting & Repair Model GFC7001E Carbon Dioxide Analyzer
Teledyne Analytical Instruments 270
Table 13-1: Warning Messages – Indicated Failures (cont.)
WARNING
MESSAGE
FAULT CONDITION POSSIBLE CAUSES
SAMPLE TEMP
WARN
Sample temperature is < 10
o
C or >
100
o
C.
Ambient temperature outside of specified range
Failed bench heater
Failed bench temperature sensor
Relay controlling the bench heater
Failed relay board
I
2
C bus
SOURCE WARNING
Occurs when CO Ref is <1250
mVDC or >4950 mVDC.
Either of these conditions will result
in an invalid M/R ratio.
GFC Wheel stopped
Failed sync/demod board
If status LED’s on the sync/demod board ARE
flashing the cause is
most likely a failed:
IR source
Relay board
I
2
C bus
IR photo-detector
SYSTEM RESET
The computer has rebooted.
This message occurs at power on. If you have not cycled the power
on your instrument:
Failed +5 VDC power,
Fatal error caused software to restart
Loose connector/wiring
WHEEL TEMP
WARNING
The filter wheel temperature is
controlled at 68 2
°
C
Blocked cooling vents below GFC Assembly. Make sure that
adequate clear space beneath the analyzer.
Analyzer’s top cover removed
Wheel heater
Wheel temperature sensor
Relay controlling the wheel heater
Entire relay board
I
2
C bus
13.1.2. FAULT DIAGNOSIS WITH TEST FUNCTIONS
Besides being useful as predictive diagnostic tools, the test functions viewable from the front panel can be used
to isolate and identify many operational problems when combined with a thorough understanding of the
analyzer’s Theory of Operation (see Section Error! Reference source not found.).
The acceptable ranges for these test functions are listed in the “Nominal Range” column of the analyzer Final
Test and Validation Data Sheet (GFC 7001E, P/N 04307 and GFC 7001EM, P/N 04311) shipped with the
instrument. Values outside these acceptable ranges indicate a failure of one or more of the analyzer’s
subsystems. Functions whose values are still within the acceptable range but have significantly changed from
the measurement recorded on the factory data sheet may also indicate a failure.
NOTE:
A worksheet has been provided in Appendix C to assist in recording the value of these test functions.
This worksheet also includes expected values for the various test functions.