Bose 2150 - Page 49

49
10.7 Make a note of the wiring, and unsolder
the red and white wires from the power
supply board.
Note: The red wire connects to the +15V
pad at W1 and the white wire connects to
the -15V pad at W2.
11. Power Transformer Removal
11.1 Perform procedure 1.
11.2 Make a note of the power transformer
wiring color code and remove the wires
that run from the power transformer (21) to
the AC Input/Output board (13) and to the
rectifier board (25).
11.3 Using a #2 Phillips-head screwdriver,
remove the four screws (22) that secure the
power transformer to the amplifier chassis
(23). These screws are located on the
underside of the chassis. Be sure to support
the transformer while removing these
screws.
11.4 Lift the power transformer out of the
amplifier chassis.
Re-assembly Note: The black and white
transformer primary wires should face
toward the side of the chassis.
12. Audio Output Transformer Removal
Note: There are two CV (constant voltage)
audio output transformers used in the Model
2150 amplifier; one for each channel. The
transformer closest to the side of the ampli-
fier chassis is used for the left channel and
the transformer closest to the center of the
amplifier chassis is used for the right chan-
nel.
12.1 Perform procedure 1.
12.2 Make a note of the audio output trans-
former (17) wiring color code to the AC/
Output board (13) and remove the wires
from the terminals. Make a note of the audio
output transformer wiring color code to the
amplifier module RF housing (2) and remove
the wires from the terminals.
12.3 Using a 5/16" nut driver, remove the
four nuts (16) that secure the audio output
transformer to the amplifier chassis (23).
Lift out the transformer.
13. Switch Assembly Board Removal
13.1 Perform procedure 12.
13.2 Make a note of the wiring color code
and remove the three wires that run from
the switch assembly board (15) to the power
switch (24) on the chassis (23) front panel.
13.3 Make a note of the wiring color code
and remove the three wires that run from
the switch assembly board to the AC Input/
Output board (13).
13.4 Remove the two screws (12) that
secure the switch assembly board to the
amplifier chassis. These screws are located
on the underside of the chassis near the
power switch. Lift out the switch assembly
board.
14. AC Power Switch Removal
14.1 Perform procedure 1.
14.2 Make a note of the switch wiring, and
remove the three wires that run from the
switch assembly board (15) to the AC power
switch (24).
14.3 Using a flat-blade screwdriver, press in
the tabs on the top and bottom of the AC
power switch that retain it in the front panel
opening. Slide the switch out of the chassis
(23) front panel.
Re-assembly Notes:
1. Align the AC power switch (24) with the
chassis (23) so the the 1b terminal is facing
upward (the 1b marking is stamped on the
side of the switch). Slide the switch into the
front panel opening.
2. The wiring should be as follows:
• Red - 1b
• Black - 1
• Brown - 1a
DISASSEMBLY PROCEDURES