Bose A20 Aviation Owner's Manual page 33

English Tab 2, 10
Problem
Low rumbling
sound with the
headset turned on
in a quiet
environment.
Crackling sound
audible with
headset turned on
in a loud
environment, or
Acoustic Noise
®
Cancelling noise
reduction is
intermittent.
Auxiliary audio input
Problem
No audio from
auxiliary source.
Audio in one ear
only from the
auxiliary input.
Tab 3, 11 Tab 4, 12
• Adjust the earcup fit to create a better seal on your head. The
low-force design of the headset makes it sensitive to items that
interfere with the seal around your ear. Make sure your ears are
completely inside the ear cushions, and that a hat or eyeglasses
with thick temples do not interfere with the seal.
• Check ports at the outside surface of each earcup to ensure that
they are not blocked. If dust or dirt is present, carefully remove
the debris using tweezers. Do not blow out or vacuum debris.
• Inspect the seal between the ear cushion skirt and the earcup.
The skirt should fit into the slot on the earcup with no gaps.
Replace any cushions that appear to be worn out.
• Ensure the headset orientation is correct. Use the Left (L) and
Right (R) markings above the earcups to orient the headset
correctly.
• Adjust the earcup fit. Refer to "Wearing and adjusting the head-
set" on page 13.
• If your headset is battery-powered, check to see if the battery is
low (indicated by fast blinking red LED).
• If your headset is aircraft powered, make sure the voltage
powering the headset is no less than 10 VDC.
• Inspect the seal between the ear cushion skirt and the earcup.
The skirt should fit into the slot on the earcup with no gaps.
Replace any cushions that have surface tears, torn stitching
joints, large wrinkles, or have become dried and stiff.
• Turn source volume up.
• Try another source with the headset to eliminate the source as
the possible problem.
• Make sure multifunction switch is not set to the bottom (intercom
only) position. The multifunction switch must be either in the top
or middle position for audio from an auxiliary input to be enabled.
• Check the connection between the auxiliary source and the
control module. Both ends of the AUX IN connector cable must
be properly seated inside the sockets.
• If the multifunction switch is set to the prioritized position (top),
the auxiliary audio source will not be heard if there is an audio
signal from the intercom.
• Check the connection between the auxiliary source and the
module. Both ends of the AUX IN connector cable must be
properly seated inside the sockets.
• Make sure the earcup cover on the headset is in place and
properly connected. Refer to "Attaching the microphone
assembly" on page 8.
Tab 5, 13 Tab 6, 14
What to do
What to do
Tab 7, 15 Tab 8, 16
T
ROUBLESHOOTING
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