KDE Plasma black screen/no video output on login

Question

What happened:

• I launched a game via proton(GTAV, lutris, epic games) and suddenly the screen turned black/switched to standby. My PC didn't react to anything; I had to shut it down by cutting off power.
• If I login with SDDM the same thing happens after the splash screen animation.
• I can switch to the tty but it needs almost a minute to "load" it.
• I have another DE/WM installed, it works flawlessly(same user)
• If I login to plasma with another user it also works as expected
• Removing the .config file in the users directory didn't change anything
• Idk if it is even related but trying to launch plasma_session from a terminal returns org.kde.plasma.session: process job "kcminit_startup" finished with exit code 0
• Launching plasmashell from terminal in a WM spits out a few warnings but works just fine(plasma panels etc. appear)
• I couldn't find anything in /var/log and with journalctl
• KDE Plasma, Xorg, Arch Linux, Zen kernel

What can I do?

Has someone an idea what causes the trouble or how I can find useful (debugging)information/logs?

Thanks in advance :)

Answer 1

I still don't know what exactly happened but after reinstalling all plasma packages it works just fine again.