BOSE 271885-B2 Schematic

SERVICE BULLETIN
Component
From
Part Number
To
Part Number
R336
2.2 Ohm
133625-2R25
10 Ohm
133625-10R0
Bulletin Part Number: 271885-B2
Product: Companion® 3 Multimedia Speaker System
Subject: No Audio Output
Disposition: All units in for repair with a no audio complaint.
Symptom: No audio output from the system and the control pod LED is dimly lit.
Reason: Q303 on the main PCB is defective or shorted completely.
base and emitter junction. Polarity is very important. Connect the cathode of the diode to the base and the anode to the emitter. Refer to the figures below for the location of Q303 and orientation of the diode. Also replace R336, as identified in the table below. Refer to the Companion 3 Speaker System service manual part number 271885-SM.
1N4148 Diode
Date: 09/04 FINS: 1569
Q303
J301
1
2
3
TP370 TP371
PGND
+15V
TP372 TP373
R308
1.00K
R336
TP378
2.2ohm
TP325 TP328
Add Diode
D301
13v
C
B
C
A
E
C
A
Q303
2SC4695
1
2
C311 10uF
AGND
1
2
+10V
C313 100uF
R313-NV
AGND
Bose Corporation; The Mountain, Framingham, Ma. 01701-9168
Service documentation available online at http://serviceops.bose.com
TP330
+10V
R337 402
R316 249
MMBT3906
Q304
R336
TP334
R317 249
TP377
MMBT3906
Q306
IABC1
R319 249
TP375TP376
MMBT3906
Q307
IABC2
IABC3
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