computer fails to start

ok have been having the weirdest problem with my computer all of a sudden. it was late at night and i decided to turn off my computer and it was working just fine when i did. but now when i turn it back on, the screen stays completely black, no beeping (which i find strange), and both my CD-RW and DVD-RW have their LED lights staying on constantly. ive tried everything from clearing the CMOS, removing the battery for the CMOS, removing the video card and reinserting it. this is just way to sudden that i cant figure this out on my own this time. if someone can help me with this i would greatly appreciate it.