Read Sharp LC-37GA8EK (serv.man9) Service Manual online
42
LC-26GA5E
LC-32GA5E
LC-32GA8/LC-32BV8
LC-37GA8/LC-37BV8
37
LC-32/37GA8E/RU
LC-32/37BV8E/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 IC1 (INV-CTL) on the
inverter unit?
inputted at IC1 (INV-CTL) on the
inverter unit?
Check the line between CN3 and
IC1.
IC1.
NO
Are the Q16-Q19 transistors at the
primary side of T1 functioning?
primary side of T1 functioning?
Replace IC1 (INV-CTL) or check its
peripheral circuits.
peripheral circuits.
NO
Is the secondary circuit of T1-T8
functioning?
functioning?
Replace the T1-T8 transformer for
the fluorescent tubes, or check their
peripheral circuits.
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 CP4/CP3/CP1
fuse on the inverter unit. Turn on the
power again. If the fuse gets blown
out again, check the short-circuited
fuse on the inverter unit. Turn on the
power again. If the fuse gets blown
out again, check the short-circuited
Check T1-T8 and their peripheral
circuits as well as Q16-Q19 and their
peripheral circuits.
circuits as well as Q16-Q19 and their
peripheral circuits.
NO
YES
YES
Is the power supplied to CP3 on the
inverter unit?
inverter unit?
Is the CP4/CP3/CP1 fuse in the
inverter unit circuit functioning?
inverter unit circuit functioning?
Check the connection between
power unit and inverter unit.
power unit and inverter unit.
NO
NO
Are there the INV-ON and INV-BRT
signals at P704 on the power unit,
and the (INV-ON and INV-BRT)
signals at SC1702 on the main PWB?
signals at P704 on the power unit,
and the (INV-ON and INV-BRT)
signals at SC1702 on the main PWB?
Check pins (5) and (7) of IC1710
(main PWB).
(main PWB).
YES
YES
YES
YES
Are there control signals (INV-ON,
INV-BRT, PWM-SEL) at CN3 on the
inverter unit?
INV-BRT, PWM-SEL) at CN3 on the
inverter unit?
NO
Check the circuit connected with the
VCC terminal on the inverter control
IC (IC1).
VCC terminal on the inverter control
IC (IC1).
Is the VCC power supplied to the
inverter control IC (IC1) on the
inverter unit?
inverter control IC (IC1) on the
inverter unit?
Backlight failure to light up
<32”>
Troubleshooting Table (continued)
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