(b)  
Make sure the highest value from the sound level meter shows as

 follows: Speaker_______ Sound Level PSU 109 -1dB +4dB Galley (ceiling) 109 -1dB +4dB Attendant (ceiling) 109 -1dB +4dB Lavatory 109 -1dB +4dB
 I. Flight Mode Test
 S 865-078
 (1)  Set the sound level meter to the SLOW and ALL PASS positions.
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757 MAINTENANCE MANUAL
 S 865-079
 (2)  
Momentarily dry-motor the left engine, refer to the operating procedures (AMM 71-00-00).

 S 735-080

 (3)  
At the same time, move the sound level meter across the speaker panel.

 (a)  Make sure the measured sound level is 6 | 2db more than the value written in the Speaker Sound Level Test.
 NOTE: It is necessary to compare only one speaker.
____
 J. Decompression Mode Test
 S 865-267
 CAUTION: MAKE SURE THE CIRCUIT BREAKERS "PASSENGER OXYGEN LEFT" (11A21)
_______ AND "PASSENGER OXYGEN RIGHT" (11A23) ARE OPEN. IF THEY ARE CLOSED, THE PSU OXYGEN MASKS WILL COME DOWN.
 (1)  Open this circuit breaker on the overhead circuit breaker panel, P11, and attach DO-NOT-CLOSE tags:
 (a)  
11A21, PASSENGER OXYGEN LEFT

 (b)  
11A23, PASSENGER OXYGEN RIGHT

 S 865-247
 (2) Make sure these circuit breakers on the P11 panel are closed:
 (a)  
11A24, PASSENGER OXYGEN CONT

 (b)  
11A25, PASSENGER OXYGEN MANUAL DEPLOY

 S 865-199
 (3)  On the overhead panel, P5, push the PASS OXY switch to the ON position.
 (a)  Make sure the PASS OXY ON light comes on.
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MAINTENANCE MANUAL

 S 735-084
 (4)  At the PA speaker, move the sound level meter across the speaker panel.
 (a)  Make sure the measured sound level is 3 | 1db more than the values written in the Speaker Sound Level Test.
 NOTE: It is only necessary to compare one speaker.
____
 NOTE: If the Decompression Test and Flight Mode Test are done
____ at the same time, the required sound level will be 9 |2db more than the values recorded in Speaker Sound Level Test.
 S 865-085
 (5)  Open this circuit breaker on the P11 panel:
 (a)  11A24, PASSENGER OXYGEN CONT
 S 865-049
 (6)  Close this circuit breaker on the P11 panel:
 (a)  11A24, PASSENGER OXYGEN CONT
 S 865-086
 (7)  
On the overhead panel, P5, make sure the PASS OXY ON light goes off.

 S 865-087

 (8)  
Remove the DO-NOT-CLOSE tags and close these circuit breakers on the P11 panel:

 (a)  
11A21, PASSENGER OXYGEN LEFT

 (b)  
11A23, PASSENGER OXYGEN RIGHT

 S 865-088
 (9)  
At the random noise generator, set the PWR/PTT switch to the OFF position.

 S 865-050

 (10)
 Disconnect the random noise generator from the hand microphone jack.

 K.  GUN 001-007, 051; Boarding Music Test (WITH RACK-MOUNT TAPE REPRODUCER)
 S 735-090
 (1)  Do these steps at the forward attendant panel, P21.
 (a)  Slowly turn the MUSIC control from the OFF position to the HI position. 1) Make sure you hear the boarding music clearly with a sound
 level that increases.
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