Does the computer go through post? Do you get a grub menu at first? I'm not certain from your description whether you can even start the boot process or whether you have a video problem.
If you don't even get a grub menu, then the installation of grub may have failed. When you start to boot up with you live distro disk, get into the grub shell instead. From there, you can use tab completion to enter in the kernel and initrd lines, and then try to boot.
The lines you enter should look something like this:
Your kernel version may vary, the partition (e.g (hd0,5) ) will probably be different. You can start out entering (hd and press the tab key to discover which drives you have. Then enter one of them, a comma and press the tab key again. You will be presented with the partitions it found. Try each one if you don't know which it is until you find either the directories of a root partition, or the contents of a /boot partition. It depends on whether you have a partition for /boot or if it is a directory. If it is a directory, you can continue entering as much as you know and pressing tab to discover the rest.
This may enable you to manually boot into suse when the MBR is messed up.
If you did start booting before but the screen went blank:
From your live disk, mount the root partition. Look at the /var/log/boot.msg, /var/log/boot.log, /var/log/messages, /var/log/Xorg.0.log log files. Check where the boot process stopped. If it is a video problem, errors show up on lines beginning with (EE).
Suppose you have a video card driver problem. You could edit your /etc/X11/xorg.conf file and use the "vesa" generic driver. If you have an nvidia card, you can use the non-accelerated "nv" driver. Hopefully after rebooting you will get at least console video.
Blank video can have a three causes. A) Monitor select was wrong so the vert and horiz refresh are off. B) wrong driver. C) Modelines are wrong.
Selecting a generic driver, you can then concentrate on selecting the correct monitor in "sax2". If you have a monitor with odd dimentions, you could use the "gtf" program to generate modelines you can use. However this probably won't be the case until you get farther along.