(b)
If the DEU shows FAILED, then do these steps:
1) Replace the DEU, M1808 (No. 1) or M1809 (No. 2). These are the tasks: Display Electronic Unit Removal, AMM TASK 31-62-21-000-801, Display Electronic Unit Installation, AMM TASK 31-62-21-400-801.
2) Do this task: Marker Beacon System -System Test, AMM TASK 34-32-00-730-801. a) If the indications are normal, then you corrected the fault.
-------------------------END OF TASK ---------------------------
EFFECTIVITY SIL ALL 34-32 TASK 803
D633A103-SIL BOEING PROPRIETARY -Copyright # Unpublished Work -See title page for details Page 206 Feb 15/2009
801. Low Range Radio Altimeter (LRRA) BITE Procedure
A. General
(1)
You do the Low Range Radio Altimeter (LRRA) BITE self-test at the front panel of the LRRA receiver/transmitter.
(2)
The LRRA system has two receiver/transmitters. The LRRA receiver/transmitters are on the E3 rack in the electronic equipment compartment.
SIL 001-003; AIRPLANES WITH ALLIED SIGNAL LRRA
(3) The LRRA receiver/transmitter BITE test does a self check for existing internal and external faults. Results of the BITE test are displayed on the LCD screen on the front panel of the LRRA receiver/transmitter.
SIL 004-021, 101-999; AIRPLANES WITH COLLINS OR THOMPSON LRRA
(4) The LRRA receiver/transmitter BITE test does a self check for existing internal and external faults. Results of the BITE test are displayed on the front panel of the LRRA receiver/transmitter.
SIL 001-003
(5) The LRRA receiver flight fault memory stores fault data from previous flight legs. You can view faults that occurred on previous flight legs to help isolate an intermittent fault that is not found by the BITE self-test.
SIL ALL
B. BITE Procedure
(1) Do the applicable BITE procedure for the LRRA receiver/transmitter.
NOTE: Refer to Maintenance Tip 737 MT 34-036 for additional LRRA troubleshooting information.
SIL 004-021, 101-999; AIRPLANES WITH COLLINS LRRA
(2) Push and release the TEST button on the front panel of the LRRA receiver/transmitter to start the BITE test.
(a)
Make sure that these indications occur:
1) All the lights come on and then go off.
2) The green light stay on for 30 seconds.
(b)
Refer to the table at the end of this task to find the fault isolation task for the applicable maintenance messages.
SIL 001-003; AIRPLANES WITH ALLIED SIGNAL LRRA
(3) Push and release either of the two switches on the front panel of the LRRA receiver/transmitter to start the BITE self-test.
NOTE: If no switch is pushed for five minutes on the LRRA Receiver/transmitter while in the self-test mode, the LCD screen will return to the normal mode screen automatically.
(a)
Make sure the LCD screen shows RADIO ALTIMETER TEST IN PROGRESS.
(b)
When RADIO ALTIMETER TEST COMPLETE NO FAILURES is shown, no internal or external hard faults were found by the self-test.
(c)
Do this step if RADIO ALTIMETER TEST COMPLETE FAILURES is shown: 1) Push the right switch under the WHY? prompt.
(d)
Do the step(s) that follow if RADIO ALTIMETER FAIL is shown: 1) Refer to the Maintenance Message table to find fault isolation task.
EFFECTIVITY SIL ALL 34-33 TASK 801
D633A103-SIL BOEING PROPRIETARY -Copyright # Unpublished Work -See title page for details Page 201 Jun 15/2010
(e) Do these steps if RADIO ALTIMETER OK/EXTERNAL FAILURES PRESENT is shown: 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-600/700/800/900 FAULT ISOLATION MANUAL 故障隔离手册 导航(119)
