[Urgent] Labtop wont start up at all

Hello,
it was immediately after a clean shut down, its on vista home premium x86
the LED for batter and AC adapter is working
1¬2 sec after i pressed the power button twice ,the power LED light goes on,
then I can hear my hard drive start spinning, bios screen or the fujitsu logo doesnt come up, theres is no screen at all, the screen just remains black, and it isnt the sound of booting when it's normal,this is much quieter,the fan is not on, the LEDs for the 3 locks(CAP, Num, and Scroll) are flashing slowly,
then laptop switches off itself, and startup again, again i can hear the hard disc spinning slowly and lights flashing, but it wont switch off at this time, and just stay the same forever, I have tried to insert a Disc, it does start reading,but nothing comes up, and then the disc drive stop after a few second.

I have not plugged in any external devices,
i have tried reseating hard drive and RAMs to different slots,
I have tried booting with just AC adapter
and that method of turning it upsidedown, holding button for 30sec.

still not working, are there anyone that encountered this b4, can anyone help????
thanks for any helps