DOWNLOAD Panasonic SA-XH175EE / SA-XH175GS / SC-XH175EE Service Manual ↓ Size: 8.27 MB | Pages: 127 in PDF or view online for FREE

41

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(s)

Checking items

Possible Fault(s)

Remarks

Set cannot Power ON:
Condition 1: 
With Standby LED on

1 Photocoupler PC5702,

PC5799

1 PC5702/PC5799 solder crack,

dry joint , short circuit, open  
circuit, etc

2 Switching IC IC5701

1 AC cord

2 AC Inlet P5701

1 Faulty AC cord, loose  

connection

Solder crack, dry joint, short  
circuit, open circuit, etc

2

Solder crack, dry joint, short  
circuit,open circuit,etc

4

Check FFC connection/ 
alignment from SMPS
(CN5700) to Main (CN2004)

2

2 P5701 solder crack, dry joint  

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

3 Switching IC IC5799

Set can Power ON  
then F61

Set can Power ON  
then F76

Set can Power ON  
working normally for
sometime then F61

Condition 2: 
With Standby LED Off 
or flickering

3 F1 Fuse open

3 Fuse F1

1 DC-DC Voltages

1 Thermal Diode D5802

2 SMPS FFC loose

(No Connection)

3 +9V (Power supply  

line)

4 Photocoupler PC5720

1 Transformer T5701

(Secondary supply)

2 Photocoupler PC5720

1a Pin 11/12 shorted to pin 13/14

1b Pin 16 shorted to pin 17

1a L2902 Open (no +18V input to  

IC2901)

1b Faulty IC2901 (no output  

voltage at pin 10 and 11)

1a Improper contact between  

D5802 to heatsink

1b OTP (thermal) protection  

trigger prematurely

3a Faulty Q2904 Transistor diode  

check (cannot switch ON then
NO +9V)

3b LB2761 Open (+9V line going  

to Panel PCB CN2002)

1c Faulty Q2902 and Q2903  

(regulator)

1d L2904, L2908 open  

(No DC +5V)

1e R2399 open (No DC +9V)

1) Refer to Fig. 1. SMPS P.C.B.

Refer to Fig. 1. SMPS P.C.B.

Refer to Fig. 1. SMPS P.C.B.

Refer to Fig. 1. SMPS P.C.B.

Refer to Schematic Diagram of
SMPS Circuit (Item 17.6) for
terminal pin count on primary and
secondary terminals

SMPS Circuit (Item 17.6)

2) Refer to Schematic Diagram of

1) Refer to Fig. 2. Main P.C.B.

Main Circuit (Item 17.2)

2) Refer to Schematic diagram of

1) Refer to Fig. 2. Main P.C.B.

Main Circuit (Item 17.2)

2) Refer to Schematic diagram of

42

Fig. 1. SMPS P.C.B.

43

Fig. 2. Main P.C.B.

44

DVD Laser Diode Current Measurement

CD Laser Diode Current Measurement

1. Measurement the voltage (V

CD

) on the testpoints CL8530(+) & CL8531(-).

This is voltage across R8566 which has a resistance value of 4.7 ohm.

2. Calculate the CD Laser current by the following formula:

1. Measurement the voltage (V

DVD

) on the testpoints CL8530(+) & CL8532(-).

This is voltage across R8556 which has a resistance value of 4.7 ohm.

2. Calculate the DVD Laser current by the following formula:

Refer to 10.1.2. 
Main P.C.B. 
(Fig. 2. Main
P.C.B.)

Refer to 10.1.2. 
Main P.C.B. 
(Fig. 2. Main
P.C.B.)

3. Specification for CD laser current is

58 mA

3. Specification for DVD laser current is

58 mA