<< Solved >> Backlight comes up after about 3 minutes after login

[mysticfact]

Hi everyone,

I have installed the MacOS Catalina, and after post install, I faced the problem of no backlight for initial period of time.
My laptop is Lenovo s730-13iml.

CPU: i7-10510u
Mem: LPDDR3 16G
GPU: intel UHD 620
WiFi & Bluetooth: BCM94350ZAE (DW1820A)

However, after about 3 minutes backlight comes up.
I have full QE/CI with UHD 620.
I have the brightness slider, in the display setting, and can change the brightness.

I read these threads:
https://www.tonymacx86.com/threads/black-screen-3-minutes-after-booting-coffeelake-uhd-630.261131/

[Guide] Laptop backlight control using AppleBacklightFixup.kext

Overview This is going to be a quick guide for how to implement backlight control for laptop internal displays on macOS/OS X. There is the original backlight guide using ACPIBacklight.kext or IntelBacklight.kext here...

www.tonymacx86.com

However, same result.

Problem reporting file is attached below.

Thanks a lot in advance

 

[mysticfact]

Add boot argument -igfxblr (to fix backlight registers on KBL, CFL and ICL platforms).
Problem solved.

 

[Hla63]

Hello i already have the same problem too and i had to add these lines enable-backlight-register
in addition to -igfxblr argument

<key>enable-backlight-registers-fix</key>
                <data>AQAAAA==</data>

to PciRoot(0x0)/Pci(0x2,0x0) Device properties.

 

[mysticfact]

Hello i already have the same problem too and i had to add these lines enable-backlight-register
in addition to -igfxblr argument

<key>enable-backlight-registers-fix</key>
                <data>AQAAAA==</data>

to PciRoot(0x0)/Pci(0x2,0x0) Device properties.

-igfxblr and enable-backlight-registers-fix is same function.
Thanks.

 

[Hla63]

Thanks.