4. To replace the half of the PC board inside the sensor housing, disconnect from the wire harness andremove the single M4 button head screw that holds it to the housing. Perform the Pre-use Checkout.5. To replace the calibration fan, disconnect its electrical connector and remove the 4 self tapping screwsthat secure it to the sensor housing. Install replacement fan so flow arrow on side points up into chassis.Perform the Pre-use Checkout.6. To replace sensor housing plug assembly, disconnect it from the sensor cable, and use a 7/16” openwrench to unscrew it from the housing, then disconnect its other electrical connector. In addition to takingstatic sensitive precautions, take care not to touch the sensor portion of the assembly with your fingers toavoid contaminating it. After you replace the plug assembly, perform the Pre-use Checkout.5.9.3.2 Calibration Valve1. Slide drawer to one side and remove three M4 screws that secure bottom cover to chassis.2. Remove the humidifier reservoir by pulling forward from bottom. A sheet metal ground strap is locatedbehind the reservoir. Remove the M3 screw that secures the strap to the bottom cover. Slide drawer toother side and remove remaining three M4 screws that secure bottom cover to chassis. Remove the coverby sliding out toward the right side of the unit.3. Disconnect the ground cable from bottom cover. The ground cable is secured to a 4mm stud in the bottomcover with a nut and two internal tooth lock washers.4. Disconnect the cooling fan cable.5. Use a 2.5 mm hex key to remove the M3 screw that secures the center of the sensor housing to the chassis.Refer to “Figure 5-16 Sensor Housing”.6. Use a 10mm nut driver to remove the two stand-off fasteners that secure the sensor housing to thechassis.7. Disconnect tubing from chassis and heat-sink vent fittings.8. Disconnect all harnesses from sensor housing, and remove sensor housing from unit.9. Remove the two M4 flat head screws that secure the calibration valve to the sensor housing, and removecalibration valve assembly.10. Install new calibration valve assembly. Connect the black wire to the - terminal and the red to the +terminal.11. Perform the Pre-use Checkout and Leak Check.© 2001 by Datex-Ohmeda, Inc.. All rights reserved. 6600-0356-000 103 95Chapter 5: Repair Procedures
