BOSE COMPANION 3 II Schematic

Troubleshooting Tips

Companion® 3 Series II Multimedia Speaker System

Refer to the Companion® 3 Multimedia Speaker System service manuals, part number 297700
for schematics, PCB layouts and parts lists.

Preventative Repair Measures
Note: Perform the following on all units returned for repair.

Product Check Action

Units built before 10/23/2007
(DOM 7289).

Companion 3
series II

Units built before 10/23/2007 will have the Aishi
capacitor C7 installed on the power supply PCB.
Replace C7 with a United Chemi-Con (UCC)
capacitor. Refer to the service manual for the part
number. The DOM cut-in date only applies to U.S.
variants. Refer to Service Bulletin:
further information.

271885-B4 for

Troubleshooting Tips

Product Symptom Check Action

Intermittent power Either J308 or the

control pod itself can be
defective

Companion 3
series II

Intermittent power Check J1 Sometimes J1 is not seated

Companion 3
series II

No Audio Check U301 Check pins 6 and 20 for 15Vdc. If

Companion 3
series II

Use a test control pod to identify if
the problem is with the customer's
control pod or the connector J308.
If the test control pod works, the
problem can be identified as the
customer having a defective control
pod. If the control pod does not fix
the problem, J308 is the failed
component. J308 is not repairable.
The module assembly would have
to be replaced. Refer to the Service
Manual for the module assembly
part number.

properly and may become
intermittent. If J1 is intermittent, the
cable may need to be replaced or
reseated.

the 15Vdc is not present, check all
other power supply voltages. If the
power supply voltages are present,
inject a 1KHz signal into J302.
Check pins 14 (right in) and 15 (left
in) and then pins 17 (right out) and
21 (left out). If audio is coming in
and nothing is going out, replace
U301

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Troubleshooting Tips, continued

Product Symptom Check Action

Companion 3
series II

Companion 3
series II

Companion 3
series II

Companion 3
series II

No Audio Make sure the unit isn't

stuck in standby

No Bass Check U3 Insert a 200 mVrms, 200Hz signal

Intermittent Audio
from Left or Right
Speakers

No Audio or Dead
Unit

Check J307 With the speakers connected and

Check the Control Pod Check the pins inside the din

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.

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.

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.

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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