Panasonic SA-BT222EB, Service Manual

Page: 36 / 141

36
8 Troubleshooting Guide
8.1. Troubleshooting Guide for F61 and/or F76
Symptom
Checking items
Possible Fault(s)
Remarks
Set cannot ON
1 AC Cord 1
Faulty AC Cord,Loose connection
Refer to
2 AC Inlet P5701 2
P5701 soldier crack,dry joint,etc.
SMPS
3 Fuse F1 3 F1 fuse open P.C.B.
4 Photocoupler
PC5702,PC5799 4 PC5702/PC5799 sildier crack,dry joint ,short
circuit,open circuit,etc
Fig 1.
5 Switching IC IC5701 5 Faulty IC5701
6 Switching IC IC5799 6
Faulty IC5799
Set can ON 1 Transformer T5701 1a Short circuit between Pin 14 and pin 16
then F76
1b
Short circuit between Pin 15 and pin 16
1c
Short circuit between Pin 16 and 17
2 Power P.C.B. 2a
Check connection between Power P.C.B (CN2916
& CN2917) and SMPS P.C.B (CN5802 &
CN5803)
2b
L2902 Open (No input to IC2901)
2c
Faulty IC2901 (No output voltage at pin 10 & 11)
2d
Faulty Q2902 & Q2903 (Regulator)
2e
L2907 open (No DC +12v)
2f L2908 op[en (No DC+5v)
3 3 Check cable connection between main (CN2004)
and SMPS
4 4a
Faulty IC2302
4b
LB2301 Open
5 Photocoupler 5 PC5720 solder crack
PC5720
dry joint,short circuit,open circuit,etc
Set can ON 1 Rectifier D5802 1a Improper contact between D5802
working normally to heatsink
for some time
1b
Set trigger tempriture protection
then F76
Refer to
Power
P.C.B.
Fig 2.
Refer to
Main
P.C.B.
Fig 3.
Refer to
SMPS
P.C.B.
Fig 1.