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LC-46/52XD1E-RU

6 – 21

FRC circuit failure         

Note: The SD signal (576i  480i) alone passes through the FRC circuit. (The HD signal does not go through.)

Does the image appear with the HD 
signal, but not with the SD signal ?  

Does anything unusual (which or 
blackish screen, block noise, for 
example) appear on the screen?      

Does the image look unusual with 
the power switch turned on?    

YES

YES

YES

Is the power supplied to IC3301 
(FRC)?  
Is there the FRC-IN signal input at pins 
(142) and (13) of IC3301? 
Check the soldering condition. 

Is there the specified RESET-A signal 
input at pin (39) of IC3301(FRC)? 
(60 ms delay design)     

Check the connection between pin 
(R22) of IC3002 (V-PRO.) and pin 
(142) of  IC3301 (FRC) as well as 
that between pin (N20) of IC3302 
and pin(13) of IC3301    

YES

NO

Replace IC3301(FRC).  

Check "RESET-A " signal pin(34) of 
IC1710 (FPGA).     

 

LC-46/52XD1E-RU

6 – 22

52INV         

Backlight failure to light up

Do all the fluorescent tubes light up?

NO

Check the individual fluorescent 
tubes for light-up failure.

YES

Replace any defective fluorescent 
tube (s) with new one (s).

Is the power supplied to CN7507B 
and CN7507D on the inverter unit?   

NO

Check the connection between power 
unit and inverter unit.      

YES

Iis the F7501 A/B/C/D fuse in the 
inverter unit circuit functioning?

NO

Replace the blown-out F7501 A/B/C/
D fuse on the inverter unit. Turn on 
the power again. 
If the fuse gets blown out again, 
check the short-circuited spot.     

YES

Check T7501A, T7501B, T7501C 
and T7501D and their peripheral cir-
cuits as IC7502B and their periph-
eral circuits.    

YES

Is the VCC power supplied to the 
control IC (IC7502B) on the inverter 
unit?   

NO

Check the circuit connected with the 
VCC terminal on the inverter control 
IC (IC7502B).     

YES

Has each control signal come to 
CN7508B? 
(INV-OFL,INV-OSC,INV-STB,INV-
BRT)  

NO

Have INV-OFL/OSC and the INV-
STB signal come to P1701(LB) in the 
MAIN substrate?    

NO

 Check pins (19),(17) and (89) of 
IC1710 (main PWB) .

YES

Is the specified control signal input-
ted at IC7502B (INV-CTL) on the 
inverter unit. 

NO

Check the line between CN7508B 
and IC7502B.     

 

YES

Are the Q7501A ,Q7502A, Q7503A 
and Q7504A transisters at the pri-
mary side of T7501A functioning? 

NO

Check the power line of IC7502B,its 
peripheral circuits or replace 
IC7502B.     

 

YES

Is the secondary circuit of T7501A 
functioning.  

NO

Replace T7501A or the T75*** trans-
former for the fluorescent tubes, or 
check their peripheral circuits.     

 

LC-46/52XD1E-RU

6 – 23

46INV         

Backlight failure to light up

Do all the fluorescent tubes light up?

NO

Check the individual fluorescent 
tubes for light-up failure.

YES

Replace any defective fluorescent 
tube (s) with new one (s).

Is the power supplied to CN7401 and 
CN7601 on the inverter unit?   

NO

Check the connection between power 
unit and inverter unit.      

YES

Iis the F7401 and F7601 fuse in the 
inverter unit circuit functioning?

NO

Replace the blown-out F7401 or 
F7601 fuse on the inverter unit. Turn 
on the power again. 
If the fuse gets blown out again, 
check the short-circuited spot.     

YES

Check T7401 and T7601 and their 
peripheral circuits as IC7401 and 
their peripheral circuits.    

YES

Is the VCC power supplied to the 
control IC (IC7401) on the inverter 
unit?   

NO

Check the circuit connected with the 
VCC terminal on the inverter control 
IC (IC7401).     

YES

Has each control signal come to 
CN7402B? 
(INV-OFL,INV-OSC,INV-STB,INV-
BRT)  

NO

Have INV-OFL/OSC and the INV-
STB signal come to P1701(LB) in the 
MAIN substrate?    

NO

 Check pins (19),(17) and (89) of 
IC1710 (main PWB) .

YES

Is the specified control signal input-
ted at IC7401 (INV-CTL) on the 
inverter unit. 

NO

Check the line between CN7402 and 
IC7401.     

 

YES

Are the Q7403 and Q7404 transis-
ters at the primary side of T7401 
functioning? 

NO

Check the power line of IC7401, its 
peripheral circuits or replace IC7401.     

 

YES

Is the secondary circuit of T7401 
functioning.  

NO

Replace T7401 or the T74** trans-
former for the fluorescent tubes, or 
check their peripheral circuits.     

 

LC-46/52XD1E-RU

6 – 24

 LCD failure 1

Does a single or several verti-
cal stripes appear on the LCD 
screen? 

Does a single or several hori-
zontal stripes appear on the 
LCD screen?

Do luminescent or black dots 
appear on the screen?

 Is the on-screen image rip-
pling or distorted?

Replace the LCD panel.

 LCD failure 2

The backlight func-
tions.  Does not the 
image come out in the 
LCD screen 
(screen black) ? 

Does the entire LCD 
screen look whitish all 
over?

Does the QS drive func-
tion?

 Are the data bit drop-
out?
(No solution even when 
turning on and off the QS 
drive)

Is the gamma correc-
tion as specified?

Replace the LCD control unit.