Akai LCT42Z7TAP, Service Manual

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3.The power is normal work ,but don’t backlight.
3.1 The indicator light work normal (green light ).
Please check Main board of transistor Q18 collect if not has +5v voltage.
Is true Q18 collect hasn’t +5v ,To check Q18 if fail. Or to check Q18 of base if not low.
(Low is working, high don’t work).
Please refer to attached sheet A circuit diagram.
3.2 Please check backlight of connector if not it direction is wrong or the connector of wire
compositor direction is wrong.
3.3 To check connector panel of voltage is +24v. It’s true .Then to check of the first pin if it
have +5V voltage, It’s true , than to check power board of +24v voltage ,It’s true. The panel
of backlight board is fail. The change panel of backlight board.
Please refer to attached sheet B Panel of datasheet.
4.The screen don’t have picture But have backlight.
4.1 To check to panel of voltage ,To check main board of bead L69 and L57 connect if not
OK.Then check the L69 and L57 of voltage is +12v( 27 inch panel voltage is +5v, To check
L68 and L56) . Next to check fuse F1 and connector J10 if not is +12v(27 inch panel voltage
is +5v). If isn’t please check power board of connector CON5 if has +12v( 27 inch panel
voltage is +5v).
4.2 To check to main board +12 V voltage. To check to main board IC U35 of the first pin if
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