Lenovo L340-171RH no backlight

[kalemaroni]

Customer dropped in their Lenovo L340-171RH (motherboard ID FG541 / FG741 NM-C361) because they had tried to repair their smashed screen themselves and now there is no backlight.

I confirmed the screen and cable worked in another laptop.

Anyone have any ideas of where the backlight circuitry is on these models and what the chip might be called, or any other pointers as to how to repair this?

[mon2]

Re: Lenovo L340-171RH no backlight

Can you see the graphics (without the backlight) ?

With extreme care, meter in DC volts (30v or higher) -> measure the voltage to ground of each pin on the LCD connector.

Post the measurements and their pin number.

[JaroTech]

Re: Lenovo L340-171RH no backlight

Hi, to start just check the fuse F3, you should have 20V on both sides.