A7N8X-E failure?

I noticed that my memory wasn't running at full speed and thought I
would speed it up in the BIOS. Shouldn't of attempted it when home
from work, tired and kids about, but I did. Anyway I think I increased
the FSB to 200MHz (I have Athlon XP 2800)and so when I tried to boot
got a POST about CPU overclocking. Tried to restart again and got the
same. I now dont get any POST and PC won't start. I have tried
resetting the CMOS. How can I get it started? If not what is the most
likely thing to have been killed?