Well, that is still not enought info.
Do you still have the manual that came with
you MB? If not,go to their web site and search
for the beep code. This is what your BIOS does
to tell you why it won't post. Or you can give
us your complete hardware list and someone here
may know.
Your memory may have gone bad. Have you made any
software installs or updates lately? Have you had
any electrical surges?
<font color=blue>You get what you pay for.... All advice here is free.</font color=blue>
there is probably some error in your hardware, have you made some changes the last couple of days. it can be that your video card is loose, or that you fried the ram...