|If this is your case....|
you have a legacy floppy drive connected (or you don't but you connect one), and...
the led for the floppy drive comes on briefly while booting, like it usually does, then it comes on again for a longer time, then goes out.....
then you could try a bios recovery procedure specific to your bios brand (a legacy floppy drive is required, or if your mboard is recent enough, you MAY be able to use the required files on a USB flash drive) even if you have no video, but you MUST use one of correct bios updates and the correct flash utility version, for your mboard model AND often the right mboard version or revision.
The version or revision of Asus mboard models is usually printed right beside the model number, which is printed in larger characters on the surface of the mboard, usually between the slots, or in the middle of the mboard.
If you don't see that, then you must replace the bios chip with one that is already flashed.
If the bios chip is in a socket, the chip can be removed, then there are vendors on the web you can buy such a chip from, for, say, $50.
If the bios chip is NOT in a socket, then it's soldered into the mboard. Replacing the bios chip in that case requires than an expert who has special de-soldering tools replace it - in most cases you must ship the mboard to the expert and have the expert ship it back - that will cost you more than what some new mboards cost you, and more than a used identical mboard.
An example of a vendor who can supply you with such a already flashed bios chip, or replace it if it's soldered in if you're in North America: