TROUBLESHOOTING & REPAIR PROCEDURES Model 300E Carbon Monoxide Analyzer
Instruction Manual
190 P/N 04288 Rev: A
Warning
Message
Fault Condition Possible Causes
FRONT PANEL
WARN
The CPU is unable to
Communicate with the
Front Panel Display
/Keyboard
WARNING only appears on Serial I/O COM Port(s)
Front Panel Display will be frozen, blank or will not respond.
§ Failed Keyboard
§ I
2
C Bus failure
§ Loose Connector/Wiring
PHOTO TEMP
WARNING
PHT DRIVE is >2500
mVDC
§ Failed IR Photo-Detector
§ Failed Sync/Demod Board
§ IR Photo-Detector improperly attached to the Sample
Chamber
§ BENCH TEMP too high.
REAR BOARD
NOT DET
Mother Board not
detected on power up.
WARNING only appears on Serial I/O COM Port(s)
Front Panel Display will be frozen, blank or will not respond.
§ Massive Failure of Mother Board
RELAY BOARD
WARN
The CPU cannot
communicate with the
Relay Board.
§ I
2
C Bus failure
§ Failed Relay Board
§ Loose connectors/wiring
SAMPLE FLOW
WARN
Sample flow rate is <
500 cc/min or > 1000
cc/min.
§ Failed Sample Pump
§ Blocked Sample Inlet/Gas Line
§ Dirty Particulate Filter
§ Leak downstream of Critical Flow Orifice
§ Failed Flow Sensor/Circuitry
SAMPLE PRES
WARN
Sample Pressure is
<15 in-Hg or
> 35 in-Hg
Normally 29.92 in-Hg
at sea level decreasing
at 1 in-Hg per 1000 ft
of altitude (with no
flow – pump
disconnected).
If Sample Pressure is < 15 in-HG:
§ Blocked Particulate Filter
§ Blocked Sample Inlet/Gas Line
§ Failed Pressure Sensor/circuitry
If Sample Pressure is > 35 in-HG:
§ Blocked Vent line on pressurized Sample/Zero/Span
gas supply
§ Bad Pressure Sensor/circuitry
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
SYNC WARNING Phase Lock Loop (PLL)
has lost lock on wheel
rotation.
§ GFC Wheel stopped
§ GFC Wheel rotation very slow/dragging
§ Failed Sync/Demod Board
If Status LED’s on the Sync/Demod Board ARE
flashing the
cause is most likely an a problem with the analyzer’s main
power:
§ Intermittent loss of the power supply too short to
cause a SYSTEM RESET warning;
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