Troubleshooting Guide; Troubleshooting Guide For F61 And/Or F76 - Panasonic SA-BTT775GA Service Manual

8 Troubleshooting Guide

8.1.

Troubleshooting Guide for F61 and/or F76

y p ( )
Set cannot Power ON:
Condition 1: With
Stanby LED on
Condition 2: With
Stanby LED Off or
flickering
Set can Power ON
then F61
Set can Power ON
then F76
Set can Power ON
working normally for
sometime then F61
g
1 Photocoupler PC5702,
PC5799
2 Switching IC IC5701
3 Switching IC IC5799
1 AC cord
2 AC Inlet P5701
3 Fuse F1
1 Transformer T5701
2 Photocoupler PC5720
1 DC-DC circuit
2 SMPS FFC loose
3 LDO regulator
4 Photocoupler PC5720
1 Thermal Diode D5802
( )
1 PC5702/PC5799 solder crack,
dry joint ,short circuit,open
circuit,etc
2 Faulty IC5701, pin 1 and 2
shorted, VCC short to GND, etc
3 Faulty IC5799, pin 5 and 7
shorted, VCC short to GND, etc
1 Faulty AC cord, loose
connection
2 P5701 solder crack, dry joint
etc
3 F1 Fuse open
1a Pin 11/12 shorted to pin 13/14
1b Pin 16 shorted to pin 17
2 Solder crack,dry joint ,short
circuit,open circuit,etc
1a L2902 Open (no input to
IC2901)
1b Faulty IC2901 (no output
voltage at pin 10 and 11)
1c Faulty Q2902 and Q2903
(regulator)
1d L2908 open (No DC +5V)
1e R7003 open (No DC +9V)
2 Check FFC connection/
alignment from SMPS (JW2)
to Main (CN2004)
3a Faulty QR7071 Transistor diode
check (cannot switch ON then
NO +9V)
3b LB2843 Open (+12V line going
to Panel PCB CN2002)
4 Solder crack,dry joint ,short
circuit,open circuit,etc
1a Improper contact between
D5802 to heatsink
1b OTP (thermal) protection
trigger prematurely
47
1) Refer to Fig. 1. SMPS P.C.B.
2) Refer to Schematic Diagram of
SMPS Circuit (Item 17.7)
Refer to Schematic Diagram of
SMPS Circuit (Item 17.7) for
terminal pin count on primary and
secondary terminals
Refer to Fig. 1. SMPS P.C.B.
1) Refer to Fig. 2. Digital P.C.B.
2) Refer to Schematic diagram of
Digital (Power) Circuit (Item 17.2)
Refer to Fig. 1. SMPS P.C.B.
1) Refer to Fig. 2. Digital P.C.B.
2) Refer to Schematic diagram of
Digital (Power) Circuit (Item 17.2)
Refer to Fig. 1. SMPS P.C.B.