When I have done a mobo bios flash,
I downloaded the new bios file to desktop.
I then extracted it to a floppy. A:\
I then entered bios and 1) made floppy only boot disk or 2) chose the Fx key the started bios flash for mobo.
In both cases from floppy I chose the update file and said yes, enter.
Unplug puter. Try removing the cmoss batt and put a jumper or a screw driver
across the mobos cmoss reset pins. See your manual for location.
If you have not actually got to the new bios file and started the process, you are liable to be unchanged in the bios. Double check all connections, make sure all is seated proper. If no go, remove all ram sticks but the one in lead slot. If your are using an HDTV monitors HD input, no POST screen. Use the pc input or a vga monitor, to see POST screen.