Read Sharp LC-32GD9EK (serv.man10) Service Manual online
56
LC-26GA5E
LC-32GA5E
LC-32GD9E
LC-37GD9E
42
LC-32GD9E
LC-37GD9E
TROUBLESHOOTING TABLE
(Continued)
NO
YES
YES
Do all the fluorescent tubes light up?
Check the individual fluorescent
tubes for light-up failure.
tubes for light-up failure.
NO
Is the specified control signal
inputted at IC7501 (INV-CTL) on the
inverter unit?
inputted at IC7501 (INV-CTL) on the
inverter unit?
Check the line between CN7502 and
IC7501.
IC7501.
NO
Are the Q7501 and Q7502
transistors at the primary side of
T7501 functioning?
transistors at the primary side of
T7501 functioning?
Replace IC7501 (INV-CTL) or check
its peripheral circuits.
its peripheral circuits.
NO
Is the secondary circuit of T7501
functioning?
functioning?
Replace T7501 or the T75**
transformer for the fluorescent tubes,
or check their peripheral circuits.
transformer for the fluorescent tubes,
or check their peripheral circuits.
Replace any defective fluorescent
tube (s) with new one (s).
tube (s) with new one (s).
NO
YES
Replace the blown-out F7501 fuse on
the inverter unit. Turn on the power
again. If the fuse gets blown out
again, check the short-circuited spot.
the inverter unit. Turn on the power
again. If the fuse gets blown out
again, check the short-circuited spot.
Check T7501 and T7502 and their
peripheral circuits as well as IC7501
and Z7601 and their peripheral
circuits.
peripheral circuits as well as IC7501
and Z7601 and their peripheral
circuits.
NO
YES
YES
Is the power supplied to CN7501 on
the inverter unit?
the inverter unit?
Is the F7501 fuse in the inverter unit
circuit functioning?
circuit functioning?
Check the connection between
power unit and inverter unit.
power unit and inverter unit.
NO
NO
Are there the INV-ON/OFF and INV-
BRT signals at P704 on the power
unit, and the INV-OFL and INV-OSC
signals at P1701 on the main PWB?
BRT signals at P704 on the power
unit, and the INV-OFL and INV-OSC
signals at P1701 on the main PWB?
Check pins (18), (27) and (28) of
IC1710 (main PWB) and pin (16) of
IC3003.
IC1710 (main PWB) and pin (16) of
IC3003.
YES
YES
YES
YES
Are there control signals (INV-OFL,
INV-OSC, INV-ON/OFF, INV-BRT) at
CN7501 and CN7502 on the inverter
unit?
INV-OSC, INV-ON/OFF, INV-BRT) at
CN7501 and CN7502 on the inverter
unit?
NO
Check the circuit connected with the
VCC terminal on the inverter control
IC (IC7501).
VCC terminal on the inverter control
IC (IC7501).
Is the VCC power supplied to the
inverter control IC (IC7501) on the
inverter unit?
inverter control IC (IC7501) on the
inverter unit?
Backlight failure to light up
41
LC-32GD9E
LC-37GD9E
TROUBLESHOOTING TABLE
(Continued)
Note: The SD signal (576i and 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?
but not with the SD signal?
Does anything unusual (whitish or blackish
screen, block noise, for example) appear
on the screen?
screen, block noise, for example) appear
on the screen?
Does the image look unusual with the
power switch turned on?
power switch turned on?
YES
YES
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 FRC-IN signal input at pins
(142) and (13) of IC3301? Check the
soldering condition.
Is there the specified RESET signal input
at pin (39) of IC3301 (FRC)? (60 ms delay
design)
at pin (39) of IC3301 (FRC)? (60 ms delay
design)
Replace IC3301 (FRC).
Check IC3302 (RESET).
Check the connection between pin (208) of
IC3002 (VCTP) and pin (13) of IC3301
(FRC) as well as that between pin (4) of
IC3302 and pin (6) of IC3301.
IC3002 (VCTP) and pin (13) of IC3301
(FRC) as well as that between pin (4) of
IC3302 and pin (6) of IC3301.
FRC circuit failure
Troubleshooting Table (continued)
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