This works with Gigabyte boards, I am not sure if this works with ASRock boards.
I would disconnect everything from the motherboard, Hard Drive, DVD, front USB , Floppy etc
Just have the PSU connected to the MB.
Remove all the RAM and turn on the computer.
The motherboard should beep like crazy indicating there is no RAM installed.
On a Gigabyte board if nothings happens or beeps, it indicates strongly that the MB is dead.
If you get past that point connect all your components back up, one at a time.
One more thing. you will need to put in your old graphics card for this test.