When I do the GUI install, I get
1) A long delay during video driver detect phase (I have inbuilt INTEL graphics board on toshiba i3 A665 laptop bought few weeks ago).
2) A very faint screen display for selecting language, key board, partition formating selection, etc. If you squint hard enough you can continue to install but I gave up at the partition formatting go ahead stage.

Workaround tried so far (they have not worked):
a. Attaching an external display, the display turns on when install starts, turns off during video detect (after scsi detect) phase, turns on again but does not show even the faint text/background for the install screen.
b. Trying a 32-bit centos server; same result.
c. Ubuntu works..no problems..so this must be a centos/redhat specific problem.
d. Tried LINUX resolution=800x600, believe tried the 1024 one as well, again no difference.
e. Tried text mode install, and then tried to startx, no diff, but have to play with the conf files more to see if I can make headway that way.

any advise/pointers welcome..

try using the function key, FN usually blue, on the laptop and find the blue keys that show a sun or something similar to brighten the display. Also, be plugged into power, you you weren't.

That is the first thing I tried, i.e. the function keys (FN+F7) to brighten the screen, also laptop was plugged into power at all times .. it did not seem to be a laptop physical control setting issue unless this particular laptop is defective for only CENTOS (function keys work as expected for windows on the same laptop)