EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
33-15-00
ALL ú ú 01 Page 6 ú Nov 15/93
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
MASTER WARNING AND CAUTION LIGHTS - TROUBLE SHOOTING
____________________________________________________
1. General
_______
A. Trouble shooting the master caution lights and system master caution annunciators is best done in conjunction with use of the master dim and test switch. Inoperative light bulbs can be quickly located when the LIGHTS switch is positioned to TEST. If a specific section of system master caution annunciator is inoperative, the trouble can usually be traced back to the corresponding P5 or P8 module.
B. Refer to the System Schematic Manual (SSM) or the Wiring Diagram Manual (WDM) to identify which annunciator lights will come on.
C. If an annunciator light does not come on, but tests OK with the master dim and test switch, refer to the associated system trouble shooting procedures. Certain annunciators may always be illuminated whenever the airplane is on the ground (such as door open indicators); this is normal. The following charts indicate possible light failures, probable cause and corrective action. See par. 2 for the master caution trouble shooting chart. See par. 3 for the master dim and test trouble shooting chart. The charts assume the airplane is on the ground with power applied to all systems.
D. All trouble shooting procedures are based on the assumption that wiring is OK and that electrical power is available. If the corrective action in the procedure does not correct the problem, check wiring using the wiring diagram.
NOTE: When replacing component perform electrical check for proper
____
operation before closing assembly.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
33-15-00
ALL ú ú 01 Page 101 ú Jul 15/94
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
2. ____________________________________Master Caution Troubleshooting Chart
TROUBLE PROBABLE CAUSE ISOLATION PROCEDURE REMEDY
when pressed. and annunciators caution lights extinguish master light does not master caution Left (or right) ator is on. caution annunci-system master illuminate when lights do not Master caution module. one P5 (or P8-1) systems on any illuminate for ciators do not lights and annun-Master caution indication. any system fault illuminate for ciators do not lights and annun-Master caution fault indication. is no system nate, but there ciators illumi-lights and annun-Master caution light inoperative. Master caution inoperative. caution light module or master and dimming M469 annunciation Diodes open in inoperative. logic circuit System module dimming module. annunciation and circuit in M469 diode dimming Open transistor-old to ground on Marginal thresh-of sensor. sensing circuit power and ground illuminate. Press left (or master caution lights master caution lights illuminate. If lights are illuminate while annuncia-tor is pressed, M469 module caution lights do not is faulty. annunciators fail to illuminate, system module is faulty. light is faulty. (or right) master caution goes off. If not, left light; check that light right) master caution annunciator. Observe Press system master caution caution light is faulty. TEST. Observe Hold LIGHTS switch to If one light is off, master on, M469 module is faulty. master caution lights and cator light on module. If more than one system indi-and simulate a failure for Refer to specific system annunciator. If master Press system master caution resistance to ground. Test sensors for high Replace the sensor power Observe system fault indi-CSB 69-37315-31-01. circuit assembly by doing and ground sensing printed cator. OR caution light. Replace master caution light. Relamp master dimming module. nunciation and Replace M469 an-module. Replace system dimming module. nunciation and Replace M469 an-Replace appli-cable sensor.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-300 400 500 AMM 飞机维护手册 灯 LIGHTS(19)
