Panasonic SA-PT480PH, Service Manual

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7 Troubleshooting Guide
7.1. Troubleshooting Guide for F61 and/or F76
This section illustrates the checking procedures when upon detecting the error of “F61” and/or “F76” after power up of the unit. It is
for purpose of troubleshooting and checking in SMPS P.C.B..
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