Bose Companion 3 Series II Service Manual page 32

Product
No Audio
Companion 3
series II
No Bass
Companion 3
series II
Intermittent Audio
from Left or Right
Speakers
Companion 3
series II
No Audio or Dead
Unit
Companion 3
series II
Troubleshooting Tips, continued
Symptom
Make sure the unit isn't
stuck in standby
Check U3
Check J307
Check the Control Pod
Check
At IC U301, place your positive
probe on pin 22 and the negative
probe on ground. Toggle the
control pod between mute and
standby by touching the top of the
control pod. When the LED is
green, the voltmeter should read
11Vdc. When the LED is yellow,
the voltmeter should read 0Vdc.
Insert a 200 mVrms, 200Hz signal
into J302. Check U3, pin 10 for a
signal going into the IC and check
pin 14 for the signal coming out. If
there is a signal going in but nothing
coming out, replace U3 using the
part number in the Service Manual.
With the speakers connected and
an audio source playing, wiggle the
speaker connections and listen to
see if the audio cuts out or
becomes intermittent. Before
determining the connectors as a
failure, be sure to inspect the
speaker cable for broken or
intermittent connections. J302 is
non-repairable; Replace the module
assembly.
Check the pins inside the din
connector at the end of the control
pod cable to see if any pins a
misshaped, bent or broken. Also,
inspect J308 to make sure none of
the pins has broken off. If the
control pod connector is defective,
replace it.
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Action