Sharp LC-19A1E (serv.man4) Service Manual ▷ View online
LC-19A1E-BK/WH
4 – 21
ATTENTION
In this model, the service support of the power unit is not supporting individual parts but exchanging the unit.
Please look at the above-mentioned trouble shoot as reference.
19INV Backlight failure to light up
Do all the fluorescent tubes light up?
NO
Check the individual fluorescent
tubes for light-up failure.
tubes for light-up failure.
YES
Replace any defective fluorescent
tube (s) with new one (s).
tube (s) with new one (s).
YES
Inside of INVERTER-circuit in
POWER-unit, is UR12V power supply
supplied to Q7501/Q7503/IC7501?
POWER-unit, is UR12V power supply
supplied to Q7501/Q7503/IC7501?
NO
Check UR12V-line in a POWER unit.
YES
Has each control signal come to Con-
nector (CN2)?
(LAMP_ON/OFF (6pin), LAMP_CTL
(5pin), LAMP_ERR (7pin))
nector (CN2)?
(LAMP_ON/OFF (6pin), LAMP_CTL
(5pin), LAMP_ERR (7pin))
NO
Have LAMP_ON/OFF, LAMP_CTL,
and LAMP_ERR signal come to Con-
nector (SC1204) in the MAIN unit?
and LAMP_ERR signal come to Con-
nector (SC1204) in the MAIN unit?
NO
Check IC801 (B15) (G3) pin and
IC2002 (58) pin in the MAIN unit.
IC2002 (58) pin in the MAIN unit.
YES
Is the specified control signal inputted
at IC7501 (INV-CTL) on the inverter
unit. (STB (11pin), DUTY (1pin), SS
(13pin))
at IC7501 (INV-CTL) on the inverter
unit. (STB (11pin), DUTY (1pin), SS
(13pin))
NO
Check the line between CN2 and
IC7501.
IC7501.
YES
Are the Q7501,Q7502,Q7503 and
Q7504 transistors at the primary side
of T7501/T7502 functioning?
Q7504 transistors at the primary side
of T7501/T7502 functioning?
NO
Check the drive line of IC7501, Its
peripheral circuits or replace IC7501.
peripheral circuits or replace IC7501.
YES
Is the secondary circuit of T7501/
T7502 functioning.
T7502 functioning.
NO
Replace T7501 or the T7502 trans-
former for the fluorescent tubes, or
check their peripheral circuits.
former for the fluorescent tubes, or
check their peripheral circuits.
19INV Backlight failure to light up
Do all the fluorescent tubes light up?
NO
Check the individual fluorescent
tubes for light-up failure.
tubes for light-up failure.
YES
Replace any defective fluorescent
tube (s) with new one (s).
tube (s) with new one (s).
YES
Remove SC1204 connector of MAIN
unit. When you input 3.3V to pin (9) of
SC1204 connector, check whether
UR12V are outputted to pin (13) to
(15).
unit. When you input 3.3V to pin (9) of
SC1204 connector, check whether
UR12V are outputted to pin (13) to
(15).
NO
Exchange the power supply units.
YES
Check whether AC voltage
(800VRMS) is output to connector
CN7502 and CN7503.
(800VRMS) is output to connector
CN7502 and CN7503.
NO
Exchange power supply units.
LC-19A1E-BK/WH
4 – 22
LCD failure
Does a single or several vertical
stripes appear on the LCD screen?
stripes appear on the LCD screen?
Replace the LCD panel.
Does a single or several horizontal
stripes appear on the LCD screen?
stripes appear on the LCD screen?
Do luminescent or black dots appear
on the screen?
on the screen?
Is the on-screen image rippling or
distorted?
distorted?
LCD failure
The backlight functions.
Does not the image come out in the
LCD screen (screen black)?
Does not the image come out in the
LCD screen (screen black)?
Replace the IC9201 (RSDS-transmit-
ter).
ter).
Does the entire LCD screen look
whitish all over?
whitish all over?
Does the QS drive function?
Are there data bit drop-outs?
(No solution even when turning on
and off the QS drive)
(No solution even when turning on
and off the QS drive)
Is the gamma correction as
specified?
specified?
LC-19A1E-BK/WH
4 – 22
LCD failure
Does a single or several vertical
stripes appear on the LCD screen?
stripes appear on the LCD screen?
Replace the LCD panel.
Does a single or several horizontal
stripes appear on the LCD screen?
stripes appear on the LCD screen?
Do luminescent or black dots appear
on the screen?
on the screen?
Is the on-screen image rippling or
distorted?
distorted?
LCD failure
The backlight functions.
Does not the image come out in the
LCD screen (screen black)?
Does not the image come out in the
LCD screen (screen black)?
Replace the IC9201 (RSDS-transmit-
ter).
ter).
Does the entire LCD screen look
whitish all over?
whitish all over?
Does the QS drive function?
Are there data bit drop-outs?
(No solution even when turning on
and off the QS drive)
(No solution even when turning on
and off the QS drive)
Is the gamma correction as
specified?
specified?
LC-19A1E-BK/WH
4 – 22
LCD failure
Does a single or several vertical
stripes appear on the LCD screen?
stripes appear on the LCD screen?
Replace the LCD panel.
Does a single or several horizontal
stripes appear on the LCD screen?
stripes appear on the LCD screen?
Do luminescent or black dots appear
on the screen?
on the screen?
Is the on-screen image rippling or
distorted?
distorted?
LCD failure
The backlight functions.
Does not the image come out in the
LCD screen (screen black)?
Does not the image come out in the
LCD screen (screen black)?
Replace the IC9201 (RSDS-transmit-
ter).
ter).
Does the entire LCD screen look
whitish all over?
whitish all over?
Does the QS drive function?
Are there data bit drop-outs?
(No solution even when turning on
and off the QS drive)
(No solution even when turning on
and off the QS drive)
Is the gamma correction as
specified?
specified?
