System Failure 23; System Failure 25 - GE Giraffe Service Manual

4.4.19 System Failure 23

System failure 23 indicates: During operation the system was unable to turn the incubator heater OFF.
Cause(s)
Other errors.
Defective relay
board.

4.4.20 System Failure 25

System failure 25 indicates: Fan rotation is not being detected.
NOTE: System failure 25 and FAN FAILURE are both triggered by the optical fan sensor not detecting the fan.
If this occurs at power-up a system failure 25 will activate. If it occurs after the power tests are completed the
FAN FAILURE alarm will activate.
Circumstance(s)
Fan is not turning
Fan is turning
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Action(s)
Power down the unit. During the system tests after power-up, the unit should detect
system failure 16. Follow the instructions in this manual for this failure.
If system failure 23 persists without system failure 16, replace the relay board.
Cause(s)
Fan not connected.
Fan or fan hub not
seated properly.
Defective relay
board.
Defective fan motor.
Fan is turning too
slow.
Old design fan.
Defective or
obstructed optical
sensor. Sensor holder
or sensor gasket dirty
or crazed.
Defective 50 pin
ribbon cable
between the relay
and control board.
Defective relay
board.
Action(s)
Check jack.
Verify the fan hub is properly seated all the way down on the
fan shaft and is seated in the groove at the top of the hub.
Replace relay board.
Replace fan motor.
Check fan speed in service mode, should be about 1500 RPM
in high fan speed. Note that this RPM measurement is only
tested during the power up tests.
Replace with new design fan. The new fan can be identified
by the grooves molded in the 2 black areas on the bottom
of the fan (side facing the heat sink). The old fan has smooth
surfaced black areas.
Check that sensor, sensor holder, and gasket and free of dirt or
other contaminants. Clean or replace.
Check for continuity on pin 9 (AIRFLOW). If defective replace
cable.
Replace relay board.
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Chapter 4: Troubleshooting
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