GE Giraffe OmniBed Service Manual page 95

Alarm Message Meaning
One of the
sensors is reading
out of range
(23-280 millivolts
on units with
Oxygen Probe
1.3 software
Failure
or higher) or
the difference
between the two
O2 sensors is
above 3%.
Servo oxygen
unit has never
been calibrated.
Unit will not
O2 Cal Lost-No
operate until
O2
initial calibration
is performed.
Cell voltage less
than 33 mV.
The sensor
plug thermistor
Oxygen System temperature
Failure 1 reading is out
of the range:
15C-55C.
The RH reading is
out of valid range:
Oxygen System
1-99. When out of
Failure 2
range it displays 0
in service mode.
The checksum
Oxygen System test performed
Failure 3 during power up
testing failed.
© 2001 by Datex-Ohmeda, Inc.. All rights reserved.
Cause
Defective Sensor(s)
Leak or occlusion in sensor
housing area.
Defective cable or
connection.
Defective Servo O2 board.
Perform oxygen calibration.
Earlier software versions did
not store voltages this low.
Unit is cold: <15 degrees C.
Cooling fan is not running
when the sensor housing
temperature gets above 50
degrees.
Defective sensor plug
thermistor or cable.
Defective servo O2 board.
Defective sensor plug.
Defective servo O2 board.
Defective Microcontroller.
Chapter 4: Troubleshooting
Action
In service mode sensor0 and sensor1 should be
23-280. If outside this range replace the sensors.
If in range ensure oxygen0 and oxygen1 read
within 3% of each other or replace the sensors.
Be sure sensor housing is seated properly and
the retaining screws are tight. Be sure sensor
gaskets are in place and the tubing is seated
correctly in the connectors. Check to be sure that
the two vents in the infant compartment under
the bed are not occluded.
Measure the voltage at J85.8-J85.7(sensor0)
and J85.6-J85.7(sensor1) and compare them
to displayed sensor0 and sensor1. If the
measurement is the same as the displayed,
check the cable and sensor contacts.
If the measurement is not the same as the
displayed, replace the Servo O2 board.
Run calibration.
Replace display software with 1.62 or higher.
Allow unit to warm up.
Test the cooling fan. Refer to the Tips section
(4.7.3).
Disconnect the cable and measure the resistance
of the thermistor between J85.4 and J85.5. Refer
to R/T chart (the temperature to resistance curve)
in the Tips section (4.7.3). If sensor is shorted,
open, or values don't agree with the R/T chart,
replace the sensor plug assembly or the cable.
If resistance is in range replace the servo O2
board.
Measure the humidity sensor voltage between
J85.2 and J85.1. If the voltage is outside the
range of 0.7V- 4.0V, replace the sensor plug
assembly.
If it is in the correct range, replace the servo O2
Board.
Replace microcontroller U6 on the Servo O2
board.
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