(In reply to comment #104)
> with
> > linux   /boot/<blah blah blah> radeon.modeset=0 1
> it seems it's booting but I can't see command line - only black screen or
> text line: "kernel booting... bla-bla-bla" and also no command line. Trying
> to enter anything gives nothing. But if a enter "reboot" and press Enter it
> restarts. So it gets the commands but I can't see any display output.

can you blindly type:
modprobe -r radeon
modprobe radeon modeset=1 dpm=1
dmesg > dmesg.log
reboot