Sharp LC-32GD8EE Service Manual page 55

Troubleshooting Table (continued)
TROUBLESHOOTING TABLE
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Do all the fluorescent tubes light up?
YES
Is the power supplied to CP3 on the
inverter unit?
YES
Is the CP4/CP3/CP1 fuse in the
inverter unit circuit functioning?
YES
Is the VCC power supplied to the
inverter control IC (IC1) on the
inverter unit?
YES
Are there control signals (INV-ON,
INV-BRT, PWM-SEL) at CN3 on the
inverter unit?
YES
Is the specified control signal
inputted at IC1 (INV-CTL) on the
inverter unit?
YES
Are the Q16-Q19 transistors at the
primary side of T1 functioning?
YES
Is the secondary circuit of T1-T8
functioning?
Backlight failure to light up
NO
Check the individual fluorescent
tubes for light-up failure.
NO
Check the connection between
power unit and inverter unit.
Replace the blown-out CP4/CP3/CP1
NO
fuse on the inverter unit. Turn on the
power again. If the fuse gets blown out
again, check the short-circuited spot.
Check the circuit connected with the
NO
VCC terminal on the inverter control
IC (IC1).
Are there the INV-ON and INV-BRT
NO
signals at P704 on the power unit,
and the (INV-ON and INV-BRT)
signals at SC1702 on the main PWB?
NO
Check the line between CN3 and
IC1.
NO
Replace IC1 (INV-CTL) or check its
peripheral circuits.
Replace the T1-T8 transformer for
NO
the fluorescent tubes, or check their
peripheral circuits.
39
55
(Continued)
YES Replace any defective fluorescent
tube (s) with new one (s).
Check T1-T8 and their peripheral
YES
circuits as well as Q16-Q19 and their
peripheral circuits.
Check pins (5) and (7) of IC1710
NO
(main PWB).
LC-26GA5E
LC-32/37GD8E/RU
LC-32GA5E
LC-32/37BT8E/RU
LC-32/37GD8E/RU
LC-32/37BT8E/RU