Read Sharp LC-37GD8EK (serv.man10) Service Manual online
56
LC-26GA5E
LC-32GA5E
LC-32/37GD8E/RU
LC-32/37BT8E/RU
40
LC-32/37GD8E/RU
LC-32/37BT8E/RU
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 Q7528 and Q7525
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 their peripheral circuits.
peripheral circuits as well as IC7501
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-OFL, INV-OSC,
INV-STB (ON/OFF) signals at P1701
on the main PWB?
INV-STB (ON/OFF) signals at P1701
on the main PWB?
Check pins (5), (7) and (8) of IC1710
(main PWB).
(main PWB).
YES
YES
YES
YES
Are there control signals (INV-OFL,
INV-BRT, INV-OSC, INV-STB (ON))
at CN7502 on the inverter unit?
INV-BRT, INV-OSC, INV-STB (ON))
at 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
<37”>
Troubleshooting Table (continued)
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