In Case Of Difficulty - Bose II Owner's Manual

In Case of Difficulty

Problem
Communication but no
active noise reduction in
both ears.
Active noise reduction
but no (or very low
volume) communication
in both ears.
Reduced active noise
reduction, intermittent
clicking sounds, or
communication distortion
in a loud environment.
Low rumbling sound with
the headset turned on in
a quiet environment.
Popping sound audible
with headset turned on
in a loud environment.
Squealing, whistling, or
chirping sound when the
system is turned on.
20
What to do
• Make sure that your headset is powered, and that the power switch is "ON."
• If using DC power from the aircraft, check the aircraft fuse or breaker.
• If using the NICAD battery pack, verify that it is charged.
• If using the alkaline battery pack, verify that:
– batteries are installed with the correct polarity. The negative terminal of
each battery attaches to the springs in the battery holder (refer to step 4
on page 13).
– batteries are fully seated and in contact with the top and bottom contacts
of the battery holder. If necessary, spin the installed batteries once with
your thumbs to fully seat them (refer to step 5 on page 13).
– batteries are fresh.
– the headset plug is fully seated in battery pack (refer to step 11 on page 14).
Check to see if the volume controls are turned too low (rotate up to increase
the volume).
Check the holes at the bottom of each earcup to make sure they are not blocked.
If dust or dirt has built up here, carefully use a small wire or the end of a bent
paper clip to unclog the hole. You may need to remove the microphone to clean
the holes.
• Adjust the earcup fit to create a better seal to your head. Be sure that a hat
or eyeglasses do not interfere with the seal.
• Inspect the seal between the cushion and the earcup. The cushion should
sit on the earcup evenly, without gaps.
• Check the holes at the bottom of each earcup to make sure they are not
blocked. If dust or dirt has built up here, carefully use a small wire or the end
of a paper clip to unclog the hole. You may need to remove the microphone
to clean the holes.
• Adjust the earcup fit to eliminate the sound.
• Inspect the seal between the cushion and the earcup. The cushion should
sit on the earcup evenly, without gaps.
Check to see if the ear cavity foam liner is missing or severely damaged. If so,
refer to "Care and Maintenance" (page 18).
Do not attempt to disassemble or service the inside of the earcups or other parts
of the headset. Only the microphone boom assembly, Clear Comfort
trim rings, foam liners, headband cover, and foam pad are designed for replace-
ment by the user. For instructions on how to care for your headset and how to
replace the cushions, refer to "Care and Maintenance" (page 18). If problems
®
persist, contact the Bose Aviation Headset Service Department (page 23).
TM
cushions,