/var/log/Xorg.0.log is coming up only ~3000 bytes depending on whether using startx (3273) or starting in graphical.target (2905). I don't know anything about getting a startup log from startx. Last normal size saved Xorg.0.log on a-865 TW was 5 Dec, 88kb, when it still had the Matrox 550 using VESA(0).