(6)  
Any announcement may be cancelled at anytime in the playback cycle by depressing the CANCEL pushbutton.

(7)  
The emergency announcement A-1 cannot be manually selected, but will playback on the PA system automatically whenever the passenger oxygen system is deployed. The oxygen indicator relay, R324, is the control.

5C7 
23-31-0 Page 6  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Oct 20/89 

F.  On GUN/XIA ALL EXCEPT B-2501-B-2505, B-2509-B-2512, and B-2514-B-2516, the tape reproducer is operated from the controls on the face of the unit. There are controls for selection and play of both boarding music and prerecorded announcements.
(1)  
Music

(a)  The front face of the tape reproducer has MUSIC controls for off/on/volume and selection of music channel 1 or 2.

(2) 
 Prerecorded Announcement

(a)  
The front face of the reproducer has the controls for selecting and playing prerecorded announcements. The selection is made with a numerical keyboard which selects the desired announcement by number and displays the selection in the window. Upon selecting an announcement, boarding music will cease and the reproducer will search for and key at the start of the selected announcement. The READY light indicates the completion of the search mode.

(b)  
Pushing the START button will initiate playing of the announcement. If START is pressed before the search is complete the search will continue and announcement playback will start immediately upon completion of search. The announcement will play to completion or until STOP is pressed, after which time the reproducer will return to the boarding music mode of operation before announcement selection.

(c)  
An oxygen emergency announcement has priority over and other prerecorded announcement or boarding music. This announcement is not manually selected. It will play automatically and repeat upon closing of the OXY IND relay, R324. This relay closes as part of the sequence during activation of passenger oxygen.

(3)  
All keyboard, START, STOP, and channel 1 or 2 switches backlight when closed. The channel selection 1 and 2 switches are push-on/push-off. All other switches are momentary.

(4)  
All the programs are on one C-60/90 Phillips four channel cassette tape. Two of the channels are for boarding music; one for selected announcements and the remaining channel for the emergency oxygen announcement.

(5)  
To open the door holding the cassette tape, display 90 in the window and press music channel switch 1.

5C2 
Oct 20/89  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  23-31-0 Page 7 

G.  On GUN/XIA ALL EXCEPT B-2501-B-2503, B-2511, B-2512, B-2514-B-2516, and B-2524, a self-test switch on the front panel of the PA amplifier may be used to check the operating status of the system. When the switch is set to TEST, test signals cause the amplifier to produce an audible tone which may be heard over the loudspeakers. When the switch is set to CAL, the front panel LED's are switched across an internal load for checking power output. The NORM position is used for normal system operation.
H.  On GUN/XIA B-2501-B-2503, B-2511, B-2512, B-2514-B-2516, and B-2524, self-test switches on the front panel of the PA amplifier may be used to check the operating status of the system. When the right-hand switch is set to SPKR TEST, test signals cause the amplifier to produce an audible tone which may be heard over the loudspeakers. When the left-hand switch is set to CAL, the front panel meter is switched across an internal load for checking power output.
I.  A chime within the PA amplifier sounds a single high tone over the loudspeaker when a passenger presses his attendant call switch. A two-tone chime is heard over the loudspeakers for crew call. A single low tone is heard when a passenger sign is posted.
5C8 
23-31-0 Page 8  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Oct 20/89 

A50435
5C8  Passenger Address System Circuit 
Jun 20/92  Figure 2  23-31-0 
Page 9 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 

PASSENGER ADDRESS SYSTEM - TROUBLE SHOOTING
1. General
A.  The following trouble shooting procedures are based on performance of the system operational test and are presented in a tree-type format to aid in rapid fault isolation.
B.  When a test step does not check out, find the box containing the trouble symptom and perform the stated action. Continue to follow a single line by analyzing the results of each test step until the required corrective action is determined. Perform the specified corrective action, then repeat the step at which the failure was encountered and complete the test to check out the system.
　
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