2K Monitor goes blank at login screen after bootup.

[Neal Caffrey]

Anyone experience this? I recently changed my monitor to Samsung 2K 144hz monitor and it went blank after bootup at the login screen. I need to unplug and replug my HDMI cable 2 times then it showed up.

 

[Shaneee]

Do you have Whatevergreen included in your kexts? If so try using the -rad24 boot arg.

 

[Neal Caffrey]

Do you have Whatevergreen included in your kexts? If so try using the -rad24 boot arg.

Yes, I do have Whatevergreen in my Kext folder. I tried -rad24, get the same result. My old 1080p monitor doesn't have any problem at all. Only this 2K monitor I need to plug and unplug the HDMI cable a few times to make it work.




Btw I'm still using Clover and on 10.15.1 Catalina... RX580 graphics card.

 

[tung_opeth]

remove agdpmod=pikera should fix it, i had this problem before

 

[cristianf]

i have the same problem with a samsung 2.5k monitor, DP boot to black screen if no whatevergreen/pikera, HDMI works without whatevergreen/pikera, if i change the input to diferent source or swith power in the monitor, I have black screen until replug 2 times, I thing is the monitor, in my macbook pro (no opencore/clover) i have the same problem with DP