it might be your monitor refresh rate is to high. In my place, monitor usually have 60Hz refresh rate, so, when we install linux on it and set refresh rate to default (usually 70 Hz), it might will blank. So, we must set our monitor refresh rate in X configuration file into 60Hz.
You can go to root (linux -s in lilo) when boot and then set down your monitor refresh rate in XF86Config (sound like that), or by using your distribution config.
Hope this help, sorry for my bad english..