Back light ribbon check

Hi @amalamani

The LCD panel LED backlights are powered via the LCD cable and not a separate backlight power cable.

Here's the hardware maintenance manual for the laptop.

Depending on the LCD panel type i.e. touch screen or non touch screen, go to the bottom of p.97 (103 of 120 pdf) in the manual for touch models p.104 (110 of 120 pdf) in the manual for non touch models to view the procedure how to access the LCD cable.

If the cable is damaged (usually where it passes through the hinge between the motherboard and the lid) and it's not just a loose connection (either end, motherboard or LCD panel) and it needs to be replaced search online for 00HM044 (for touch model) or 04X5449 (non touch model) to find suppliers that suit you best.

If the cable seems to be OK it could be a blown backlight fuse on the motherboard.

If the motherboard model is NM-A102 then below is the schematic showing the LCD connector pinout where I've highlighted the backlight fuse (F3) and where it supplies power to the connector (pins 27 & 28).

There is always power being supplied to the backlights. The backlights are turned off and on in the LCD panel by a signal being sent on the Backlight On lead (pin 18). Check if there is voltage on pins 27 & 28 and if it's not you need to check the fuse.

If the fuse is blown search online for 3A_32V_ERBRD3R00X to find suppliers. Also if the fuse is blown then the reason for this will need to be found as fuses generally don't fail of their own accord.

Unfortunately I cannot find a boardview file for the motherboard showing the location of the components, so hopefully the fuse will be designated on the board.

(click on image)