I have installed Manjaro KDE in a mac mini late 2014.
After installing it, I've been using it and all seems great.
I turn off PC and the next day it does not boot, after some seconds (after grub) screen turns black and says no signal... I have tried to reboot many times, I click ESC to go to menu all fine but when start booting black screen again.
What I do is to turn off PC and start pressing AltGr so MAC will access to the boot menu. I can choose the unit to boot, just choose my HD click enter and boots normal.
It is very strange and it does not happen all the time, for example this morning boot normal, I use it for a few time, tur off and 3-4h later does not boot so I have to do it as mentioned before.
Does someone else experienced any similar issue and know how to fix it?