Thinkpad x240 - flickering pixels across the screen

[jalovcan]

EDIT: SINCE I UPGRADED TO MOJAVE, A NEW POST HERE >>> https://www.tonymacx86.com/threads/thinkpad-x240-problem-with-graphics-flickering-screen.278127/


I am quite new to this and I've done a fresh install of High Sierra on a Thinkpad x240. I've installed everything what I found in the post-installation and everything seems to work fine except few issues.

1. I am experiencing a flickering of pixels across the whole screen, especially on darker background it can be seen as little colourful points appearing on the screen for split seconds. The laptop was patched with a SSDTs from another guide here on tonymacx, but assuming that I have a not so usual screen here - 1080p, could that be the issue? I also tried the guide specially for Intel HD 4400 and it doesn't seem to change.
Everything else looks great, transparency and no window flickering or anything, so just that.

2. also, both the brightness key on the keyboard make the brightness go higher, it was working before but I installed some more kext and was changing something in the config.plist but cannot figure out what.

Thanks a lot for all your help

PS. - I don't have yet installed the working WLAN card in the system, its being shipped and will install it as soon as I can. I have modded BIOS that it accepts that card - not sure if this is relevant to the problem

 

[jalovcan]

I run into another problem -

I got new WIFI card (DW 1820a) and installed it, and the system won't boot anymore. I took it out, booted in again and used RebanMan's guide to Broadcom Wifi cards but it doesn't seem to change, it still freezes while starting up, could you please help?