this is a hardware issue... your system seems to be failing the POST test... what you need to do is open up your CPU and check for any hardware device that isn't tightly screwed... Do check whether the RAM sticks are properly inserted into their respective slots or not...
not hdd problem because pc loads without it . check
not supply power, because pc turns on . check
u said i was not memory problem . check
try to unplug any card reader, cd/dvd reader ..
does your pc "beep" when while botting ?
remove CMOS battery and wait some minutes .
i'd say its graphics or memory problem .. try to use another one .. or memory failure ..
have u tried to boot with an other hdd? it could be that ur hdd have died. other then that u shud try to take out ur CMOS battery for a bit n put it back in as more ppl have said before me. also double check that everything is tightened properly n is in its place.