LC-52XL1E (serv.man3). Adjustment Procedure - Sharp TV Service Manual (repair manual). Page 18

LC-46XL1E/RU, LC-52XL1E/RU

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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 sig-
nal, but not with the SD signal?

Does anything unusual (which or black-
ish 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 (CPLD).

                      
Do all the fluorescent tubes light up?

NO

Check the individual fluorescent 
tubes for light-up failure.

YES

Replace any defective fluorescent 
tubes with new ones.

YES

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

NO

Check the connection between power 
unit and inverter unit.

YES

Is the fuse (F7401 or F7601) in the 
inverter unit circuit functioning?

NO

Replace the blown-out fuse (F7401 or 
F7601) 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 well 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 
CN7402? (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 Q7405 and Q7406 transis-
tors 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.