Panasonic SA-PT480PH

35
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
Checkin
g
items
Possible Fault(s)
Remarks
Set cannot ON
1 AC Cord 1
Fault
y
AC Cord,Loose connection
Refer to
2 AC Inlet P5701 2
P5701 soldier crack,dr
yj
oint,etc.
SMPS
3Fuse 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
Fault
y
IC5701
6 Switching IC IC5799 6
Fault
y
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
Fault
y
IC2901
(
No output volta
g
e at pin 10 & 11
)
2d
Fault
y
Q2902 & Q2903
(
Re
g
ulator
)
2e
L2907 open
(
No DC +12v
)
2f
L2908 op[en
(
No DC+5v
)
3 3 Check cable connection between main (CN2004)
and SMPS
44a
Fault
y
IC2302
4b
LB2301 Open
5 Photocoupler 5
PC5720 solder crack
PC5720
dr
yj
oint,short circuit,open circuit,etc
Set can ON
1 Rectifier D5802 1a
Improper contact between D5802
workin
g
normall
y
to heatsink
for some time
1b
Set tri
gg
er tempriture protection
then F76