Bose A20 Aviation, Owner'S Manual

Page: 32 / 44

Troubleshooting
32 - English
Problem What to do
Squealing or
whistling sound
when the headset
is turned on
• Make sure the headset orientation is correct. Use the Left (L) and
Right (R) markings above the earcups to orient the headset cor-
rectly.
• 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.
• Adjust the earcup fit to create a better seal on your head. The
headset’s low-force design 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.
• If the squealing or whistling sound persists, turn off the power
switch and contact Bose for service as soon as possible.
Low rumbling
sound with the
headset turned
on in a quiet
environment
• 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.
Crackling sound
audible with
headset turned on
in a loud environ-
ment, or Acoustic
Noise Cancelling
®
noise reduction is
intermittent
• Make sure 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 headset”
on page 15.
• 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.
Warning: If the headset emits any loud noise and related loss of communications
while in the Acoustic Noise Cancelling mode, turn off the power switch.
The headset will continue to provide communications in the passive
noise reducing mode.