contact ASUS and see what they can offer.
I recently had this problem with a Gigabyte board - I followed the flash procedure to the letter - backed up the old bios to a USB stick, flashed the new bios and it verified okay then rebooted expecting to go into the bios and set everything to defaults but it black screened so that was that I thought.
Turns out Gigabyte have a 3 year warranty and it was just within that timescale. They did the repair (which was pretty simple) and got it back to me within a week - excellent service.
Of course if your board is too old for warranty ASUS may well charge for a repair, in which case you should look on Ebay a 2nd hand Socket A board.