Servo Controlled Oxygen Troubleshooting Tips; Check Supply Valves And End Cap Safety Valve; Check Calibration Valve/Calibration Fan; Check Cooling Fan - GE Giraffe OmniBed Carestation CS1 Service Manual

5.4.4 Servo Controlled Oxygen Troubleshooting Tips

5.4.4.1 Check Supply Valves and End Cap Safety Valve

Power up device in service Mode. Close the canopy. Select Servo O2. Be sure O2 is connected. Open V1. You
should hear gas flow. Close V1, open V2. You should hear gas flow. Close V2, gas flow should stop. If supply
valves are open an there is no gas flow, check that the end cap safety valve located in the bottom of the rail
is not stuck in the closed position. Check that the two-way valve is not occluded or the spring assembly has
not failed.
If both valves are not opening, test the fuses and supply valves. Disconnect J83 at the Servo O2 board.
Measure the resistance on harness pin 1 to pin 2. It should be the supply valve resistance (50 to 100 ohms).
If not, the fuse is opened or the supply valve is defective. Repeat for the second supply valve with pins 3 to 4.
If the valves check OK, the Servo O2 board is defective.
Note: With one supply valve open the flow rate should be a minimum of 35 L/min. With both supply valves
open, the minimum flow rate should be 40 L/min. If the flow rate is low, check that the regulator inlet
screen is not occluded.

5.4.4.2 Check Calibration Valve/Calibration Fan

The calibration valve is located beneath the chassis in the sensor housing. The calibration fan is mounted in
the sensor housing next to the calibration valve. Power up device in service Mode. Select Servo O2 . Open
VC. This should open the calibrate valve and turn on the calibration fan. Verify the calibration fan is running.
If the fan is running then the Servo O2 board is OK and the calibration valve may be defective. If the fan is
not running check the control signal from the Servo O2 board to verify voltage is present when VC is opened
to determine if the fan or board is defective.

5.4.4.3 Check Cooling Fan

The cooling fan is mounted to the sensor housing door on the chassis cover. Power up device in service
Mode. Select Servo O2 on second page. The cooling fan should be running.
If fan is not running, verify 10.0 - 13.2 Volts at J86-1 to J86-2. If voltage is present, the fan is defective. If
voltage is not present, the Servo O2 board is defective. Open VC, you should hear a click and the cooling fan
should stop. If the fan does not stop the Servo O2 board is defective.
Service Manual
Chapter 5: Troubleshooting
Servo Controlled Oxygen
5-21