http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems
run down the list, every step. step 17, is a speaker connected to the motherboard? you can make one of needed.
canned diagnostic speaker rant
The diagnostic speaker is the motherboards main diag feedback device.
the motherboard may be telling you where the problem is.
my speakers have this plug
http://images.crutchfieldonline.com/graphics/infolib/homelib/hSpeakerSpringClip.jpg
I use lamp wire but any stranded wire will do. literally any stranded wires. strip one end like so
http://www.antiquelampco.com/Shades/CordColors.jpg
attach the stripped end into the speaker spring clips on the speaker.
the other end of the wire should be trimmed like so the semi strip
https://wesbellwireandcable.com/images/cutwire.png
by doing a semi strip the wire case is now the socket.
plug one wire to the first pin, and the second onto the fourth pin.
power on the system and listen for beeps
end canned rant
with a speaker connected are you getting any beeps at boot? the beep codes should be available at asrock.com .
if the checklist does not help, try removing the RAM. with no RAM installed and a speaker connected attempt to boot the system. the motherboard does not like booting with no RAM and will beeps loudly and regularly. (see site for beep definitions)
it has been my experience that a motherboard that does not beep with no RAM installed is a failed motherboard
always follow proper grounding procedures
Canned Grounding Rant-
shut down system and remove side panel. with the power cable plugged into the PSU touch a bare unpainted metal area of the case. (my favorite spot is an unpainted screw securing the PSU) once you have grounded yourself you can unplug the computers power cable from the PSU and can touch the system.
if you move your feet, or shuffle in your chair, plug in the cord, reground yourself and unplug again.
end canned rant-