The Backlight Does Not Light - Sharp LC-32LE600E Service Manual

LC-32/40/46LE600E/RU/S (1st Edition)
<Backlight BLOCK: LC-32LE600E/RU/S>
Is either of fluorescence LEDs off?
Are all fluorescent LEDs on?
Is REG3.3V supplied to pin(1) of CN7603(Driver_sub_PCB)
when the power switch is turned on?
Is UR13V supplied from pins(1-4) of connector CN7003 (PD)
when the power switch is turned on?
Is the STB_ON/OFF signal supplied from pin(8) of CN7008 (LB)?
Is each control signal of CN7008(LB) normally function?
Pin(7) OFL (PWM light control signal input)
Pin(6) ERR (Error output)
Is [LAMP_ERROR] indicated with [5] in a process mode?
Is BL_ON output to pin(2) of CN7603 when the power switch is
turned on?
Is 144V supplied to pins(2,4,6) of CN7007(LA2) and
pins(2,4,6,8,10,12) of CN7006(LA1) when the power switch is
turned on?
Check if the peripheral circuits are short-circuited or parts are
faulty.
U7651, U7502, U7601-7605, Q7501-7509, Q7601-7609

The backlight does not light

NO
YES
YES
YES
YES
YES
YES
YES
YES
YES Check each fluorescent LED, and change defective parts.
(RUNTKA595WJ01, RUNTKA598WJ01,etc.)
NO Check each fluorescent LED, and change defective parts.
(RUNTKA595WJ01, RUNTKA598WJ01,etc.)
NO Check if the peripheral circuits are short-circuited or parts are
faulty. (U7701, U7702, etc ⋅ ⋅ ⋅)
Refer to "No power supply (Front LED does not light up)" and
"No power-up even if turned on (Front LED light up)"
NO Check the peripheral circuits
(T7002, D7501, L7501, PC7001)
Refer to "No power supply (Front LED does not light up)" and
"No power-up even if turned on (Front LED light up)"
NO Check the STB signal line on the MAIN_UNIT side (pin(2) of
P7602(LB), pin(D23) of IC3303(VCT_P), etc...)
and the peripheral circuits.
NO Check each control circuit.
NO [LAMP_ERROR] is returned to the default value in a process
mode.
Check the peripheral circuits (IC7054, etc ⋅ ⋅ ⋅)
NO
NO Check if the peripheral circuits are short-circuited or parts are
faulty.
IC7251,PC7004, PC7006, T7501, D7501, C7501, FA5511,etc ⋅ ⋅ ⋅
Refer to "No power supply (Front LED does not light up)" and
"No power-up even if turned on (Front LED light up)"
5 – 3
YES
YES
YES