Just a quick update, the problem is SOLVED!

As i wrote earlier only available schematics for this model was a revision 1A, which is slightly different from our 1B. Because of that i have decided to trace the lines manually to EC and CPU to find the right ones. The ENBKL was first measured on the wrong spot, that is why it was pretty low.

After tracing the lines i was concentrated on the following two circuits ENBKL and INVTPWM. The ENBKL circuit was working without problems but i have found a problem on the INVTPWM line which wasnt 3.3V on the output. Input from the CPU...

Hi,

i have one acer Nitro 5 without backlight on my desk.

Mainboard model: LA-L031P GH53Z REV 1B

Attached schematics and boardview are REV 1A, slightly different as REV 1B.

[URL="https://www.badcaps.net/filedata/fetch?id=3448764"]11411_LA-L031P-Acer_Nitro_5_AN515-45_AN517-41-GH53Z_Rev_ (1).zip[/URL]

Repair history: customer cleaned dust and changed thermal paste, shortly after that there was no light

Notebook boots without problem and shows only image without backlight, HDMI output working. Optical inspection...