Harman JBL SUB 550P - Troubleshooting Flow Chart

Sub550P/230 Troubleshooting flow chart
yes
Stand-by BD check
+6V,-6V, Stand-by
VOL.
no
no yes
yes
no
yes
no
yes
no
yes
no
yes no
yes
no
no
yes
yes
no
.
Start
Dc voltage check
±Vcc,±15V
O
K
Check transformer
C168,C169,D123,
D124,C170
Power on check
LED red &blue
O
K
Check vol module
& connector
cable& ±15V.ect
Check THD output
power, noise
O
K
Check pre board
& power board ,
±Vcc,±15V ect
Test frequency
Response
O
K
Check U102,R124,
C104,R125,C117.ect
Test input sensitivity
O
K
Check U101,R117,
R112,R114 ect
Test protection
O
K
Check U107.R237
±15Vcc ect
Test limiter circuit
O
K
Check U106.Q107ect
Auto off Function
Hi pot test
O
K
Check U103.Q101.
Q102.C131.R142;Ac
cord, Transformer.
O
K
Listening test
O
K
The Amp ass’y ok
END
Test phase sw,low
pass sw rabos vr
Check sw103,102,
R158,163,177 ect
13