BOSE 172780 B2 Schematic

Product: BUILT-INvisible® Home Theater System

172780-B2

Subject: Distortion in 3 Room variation
Effective
Date:

11/99 Units built before 11/99

S/N:

Symptom: Distortion on the Room 3 Mono channel of the BUILT-INvisible 3 Room System

Reason: Some BUILT-INvisible 3 Room amplifiers have been built with an SMD jumper at

location JP10 instead of location JP9 on the personality module.

Solution: On all units built before 11/99, verify that the SMD jumper is installed at location JP9

instead of JP10 on the 3 Room personality module. Location JP10 should be empty.
This jumper is located in approximately the center of the PCB on the SMD side of the
board. If the jumper is installed at JP10, carefully remove it and install it in location
JP9. Refer to the schematic for the 3 Room personality module, assembly number
AS175462-02, sheet 6 of 8 and the layout diagram in the BUILT-INvisible service
manual, part number 172780 Rev. 01.
Note: This part is shown installed in location JP10 on the schematic diagram as well
as listed in the part list as JP10 in Rev. 00 of the BUILT-INvisible service manual.
The part is shown in location JP9 in the schematic diagram and listed in the
part list as JP9 in Rev. 01 of the service manual.

Details: An SMD jumper in location JP10 causes an interaction between Zone 1 (Room 2) and

Zone 2 (Room 3), resulting in distortion at the Room 3 Mono output. Removing this
jumper from JP10 and installing it in location JP9 removes this undesired interaction,
and eliminates the distortion.
Note: Changing this jumper to location JP9 will also change the amplifiers internal
switching configuration. This change is seen when using two active signal inputs to
the amplifier at the same time. See the tables below.

Active Input Signal will play

in rooms:

123
Main Input
Aux Input

•

••

Jumper in location JP10

(undesired configuration)

Active Input Signal will play

in rooms:

123
Main Input
Aux Input

••

•

Jumper in location JP9

(desired configuration)

Date issued: 11/99
ECN: 26912
FRACAS: D275

Bose Corporation

The Mountain

Framingham, Ma. 01701-9168

For Technical Assistance Call 1-800-367-4008