JBL PSW-D110 Service Manual page 13

PSW-D/DPS-10 POWER MODULE TESTING FLOW CHART
CAUTION : MODULE OUTPUT IS FLOATING AND IS NOT PROTECTED AGAINST A SHORT
TO GROUND. ALL TEST INSTRUMENTS CONNECTED TO THE OUTPUT MUST
BE FLOATING. ATTACH THE SCOPE PROBE TIP TO SPK - and REFERENCE
LEAD TO SPK+.
START
Resistance check
(no load)
between V+ V-,
V+ O/P,V- O/P
and O/P to GND
is > 5K
no
OK
yes
Power up with no
signal input
LED RED
no
OK
yes
Check input of
module wrt GND
= 0V D.C.
no
OK
yes
Use scope to
check switchi4.
High-Pass
no
OK
yes
MODULE OK
END
Replace
Module
Check fuse
transformer,
CMC, rectifier,
C1 and C2
Check C29 and
Pre-AMP
Check V+; V-;
+/-15V voltage
at the module
no
OK
yes
Check 6V at the
module wrt V-
=6.2V
no
OK
yes
Check S/D volt-
age at the module
wrt V- =5.75V
no
OK
yes
Use scope to
check O/P at
module wrt GND
90Vpp square
wave shown
no
OK
yes
Check L1, L2,
L3, L4, C6 and
C24
Check
transformer,
CMC, rectifier,
C1, C2, D9,
D10, R16 and
R17
Check D6, R9
and R46
Check D1, R1,
Q3, Q4, Q5,
and SCP
13