Does this laptop have a backlight display or is it all on the LED disp

Hi,

It is all inbuilt in the display panel and it is not a separate part.

The backlight power for the HP Pavilion 15 ay series laptops is supplied by the DC power interface section of the motherboard (+19VB) and it is turned on and off in the LCD panel by a control signal sent from the motherboard.

Here’s a composite image taken from the schematic for a LA-D704P motherboard This board is used in a HP Pavillion 15-ay series laptop, but maybe not yours. If your motherboard is a different model then here’s a link to hopefully find the schematics for your particular board. Insert the board number (printed on motherboard) in the search box at the top of the page.

It shows that the backlight power is supplied to the LCD panel cable connector on pins 27 & 28.

The backlight power feed itself is not turned off but there is a BKOFF# control signal lead (aka DISPOFF#_R) connected to pin 23, which is used to turn the backlights on and off.

Even with the backlights turned off there is power on pins 27 & 28

(click on image to enlarge for better viewing)

Hopefully this is of some help.