Since a PC/laptop doesn't need a hard disk to show the BIOS and boot (it can just as well boot from a CD, DVD or USB-stick, and if it finds nothing of those it gives an error message) I'd remove the hard disk, reboot and see what happens. If consistently the BIOS screen shows and there's a message about not finding a boot device, try booting from an optical disc (Linux, Windows Install, memtest86, whatever). None of those need a hard disk to start working.
After you did this experiments, tell the result.
Kees
hi guys
I have the problem in my laptop..
my laptop details :
satellite L640
model no PSK0LG -01D002
initially it is not displaying bios screen and no booting..
ac adapter plug indication,powern on, battery and hdd led showing indication
when i switched on power supply,i was holding fn key and repeatedly pressed f5
then windows update screen came( windows updating 15% and displayed update failed and its shown restarting
afterthat i couldnt get in to os..
so i thought os corrupted.. then i removed hdd and installed new os using other laptop and i plugged the hdd in to this laptop..
this time no bios screen .. black screen appeared and i heared the windows new hardware detecting sound ..
so i used same method holding fn+ repeatedly pressing f5.. finally i got the windows screen...i insatlled all the drivers..
when i was browsing in google chrome, processor fan increased their speed and heard fan noisy sound .. laptop suddently turned off
after that no booting no bios screen..
hard disk and RAM checked and working fine.
changed the CMOS battery and cleaned the dust on motherboard
please help me in this issue

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