I repared today the keyboard backlit. The cable had slipped out of the socket. Now it's working.
Thank you all!...

I already did the copy+paste. And I just realized the product name is false in bios. It should be "lenovo legion y540-15irh-pg0", and now it's "lenovo legion y540-15irh". Can there be a connection between keyboard backlight and the false product name/missing baseboard version?

Anyways, if there is not relation between these two things, the keyboard's backlight still not working....

Can you help me with motherboard numbers?
In the System Information the "baseboard product" is "INVALID" and the "baseboard version" is "No DPK".
What is the address of these datas? Or should I find in this interval "DMI 632000 - 633FFF"?...

Hi all!
I did the ch341a programming successfully, thanks for help!

Only one little problem: I tried everything, but the keyboard backlight is not working.
The Lenovo Vantage shows it's ON or OFF, and all other fn keys working..

This problem started when I turned off and on the laptop again and again before the bios programming. I tried turning on and off with power button and with NOVO button, too.
Does someone know the bin file contain the keyboard firmware/driver or what should I do? I tried everything.

- Lenovo Hotkey installed
...