blade 1000 configure ATI chipset

[philo <research.philo@orange.fr>]

hi,

i have installed debian R5 on Sun blade 1000, the system works.
but i tried to install x-window system, but it doesn't works.
i try :

KDE
Xfce4
Gnome

the screen block i must shutdown machine.
the video card is based on ATI chipset, the real name is Sun PGX64.
how can i parametre the x-window system.
i try also :
apt-get install x-window-system-core

there are some commands for configure ATI chipset
also i don't try tu change xorg.conf because the xserver block, i cannot see /var/log/.....
can y install ati distribution .deb on my blade.
i search the ati-xserver-xorg package .....


best regards 
philippe