1 3
Amplifier/Subwoofer
BU-150
BU-150 POWER AMP MODULE TESTING FLOW CHART
No
Yes
No
Yes
No
Yes
No
Yes
No
No Yes
Yes
H
No
Yes
No
Yes
START
Check V+,
V-, +/-15V
voltage to
module
Check fuse
transformer,
CMC,
rectifier, C1,
C2
Check
switching
frequency
100KHz
+/-10%
~1Vpp
Check I/P of
module to
GND 0V D.C.
Power up with
no signal I/P
LED RED
OK
OK
OK
OK
OK
OK
OK
OK
Check C29
and Pre-AMP
Check O/P to
module for
80Vpp square
wave
measure to
GND
Check L1,
L2, L3, L4,
C6, C24
Check 6V to
module
measure to V-
Replace
Module
Power AMP
OK
END
Check D1,
R1, Q3, Q4,
Q5 and SCP
Check
transformer,
CMC,
rectifier, C1,
C2, D9, D10,
R16, R17
Check S/D
voltage to
module (5V)
measure to V-
Check D6,
R9, R46
Resistance
check
between V+
V- and O/P
O/P to GND
should > 5K
