Bass Module Procedures - Bose 3-2-1GS Series II Service Manual

Bass Module Procedures

Equipment required:
• Audio signal generator
• dB Meter
• Distortion meter
• Digital multimeter
• 2 Ohm, 50 Watt load resistor
• Bass module test cable (see instructions
in the appendix)
Test Setup
Refer to Figure 2 for the following tests.
1. Unpowered Transformer Impedance
Test
1.1 On the bass module, set the AC mains
switch to the ON position (if applicable). For
the International variation, set the voltage
select switch to 115V.
1.2 Using a DMM, measure the transformer
input impedance through the AC connector.
For the dual-voltage variant, set the voltage
select switch to 115V. Change the voltage
select switch to 230V, and re-measure the
AC input resistance. The resistance should
be within the ranges specified below.
Part Number Region
273031-1xxxx, U.S./JAPAN,
273031-xxxxx Taiwan
273031-2xxxx International
273031-6xxxx Dual-voltage
(115V)
(230V)
2. Woofer DC Resistance Test
2.1 Remove the bass module rear enclosure
using bass module disassembly/assembly
procedure 1.
2.2 Remove the woofer harness from Jx on
the bass module PCB. Measure the DC
resistance of the woofer voice coil by mea-
suring across the two pins of the woofer
harness. It should be 1.55 Ohms + 15%.
TEST PROCEDURES
Ohms
3.5 ± 15%
9.8 ± 15%
3.7 ± 15%
9.8 ± 15%
62
3. Power Up Test
3.1 Set up the computer to communicate
smartspeaker commands with the system
using the procedures in the appendix of this
service manual.
3.2 Set up the bass module under test as
shown in Figure 2. Apply AC mains voltage
to the bass module.
3.3 Transmit two consecutive smartspeaker
commands to turn on the system and remain
muted. The commands should have at least
100msec spacing between them. The first
command will wake the system. The second
command tells the system to remain muted.
The command bytes are represented in
hexadecimal format: 0x01 0x00 0x00 0x01
space 0x01 0x00 0x00 0x01
The speaker should respond "0x00".
3.4 Select the analog inputs by transmitting
the following "SOURCE TYPE" message:
0x0D 0x00 0x02 0x0F
The speaker should respond "0x00".
3.5 Set the stream type by transmitting the
following :STREAM METADATA" message:
0x0E 0x00 0x00 0x00 0x0E
The speaker should respond "0x00".
3.6 Transmit the smartspeaker SET MAIN
ATTENUATION message to set the attenua-
tion to 12 counts (0-100): 0x02 0x00 0x0C
0x0E
The speaker should respond "0x00".