Message Name:

OVEN INOP

The galley high-heat oven is inoperative.

• Oven Power Source
• Oven
• Oven Controller
• Oven Power Relay
• Oven Compartment Door Microswitch
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Flight Operation Notifications Manual (FONM): None

NOTE: For the following troubleshooting, refer to your supplemental wiring manual.

1. Access the Oven connector and perform a 115 VAC voltage check on aircraft side as follows:
   

   From	To	Expected Result	Result
   pin A	D	115 VAC
   pin B	D	115 VAC
   pin C	D	115 VAC

   1. If 115 VAC is present, continue with next step.
   2. If 115 VAC is not present, go to step 4.

2. Reconnect the Oven connector.
3. Access the Oven controller connector. Perform a 24 VAC voltage check as follows:
   

   From	To	Expected Result	Result
   pin J	pin K	24 VAC

   1. If 24 VAC is present, replace the oven controller and do close out.
   2. If 24 VAC is missing, replace the oven and do close out.

4. Perform a wiring check between the oven power relay and the oven.

   1. If wiring defects are found, repair defective wiring as required and do close out.
   2. If no defects are found, continue with next step.

5. Perform a 115 VAC input voltage check of the three phases at the oven control relay.

   1. If the input voltage is missing on one or more phases, investigate the power source and wiring and repair as required.
   2. If input voltage is present, continue with next step.

6. Access the oven compartment door microswitch and perform a continuity check of the switch in the door-open and door-closed states.

   1. If microswitch is found defective, replace the microswitch.
   2. If no defects are found, continue with next step.

7. Perform a wiring check between the oven compartment door microswitch and the oven power relay.

   1. If wiring defects are found, repair defective wiring and do close out.
   2. If no defects are found, continue with next step.

8. Replace the oven power relay.
9. Do close out.