Computer will not load past OS

[davidpaton]

i have a fairly old pc
foxcomm G31MXP motherboard maxed out on ram (4gig)
im running windows xp sp3
intel dual core 2.8ghz (runs very hot 70c+ checked on speed fan)
i have an ati radeon 5450 newly bought

the other day i tripped and fell near my computer it then proceeded to crash ever since then it wont stay turned on for more than 20 seconds sometimes less.
it will load the bios screen and sometimes gets as far as the os system loading then will just crash im wondering if maybe ive dislodged something ? i have tried swapping the ram for the stock ram i had to rule out the bad memory problem ive tried removing the graphics card and that didnt work can anybody suggest something else ?

thanks for your time

 

[Tmagic650]

When you fell did the PC get un-plugged from the wall, or did it fall on the floor?

 

[davidpaton]

neither it just powered off it was on my computer desk im worried i may have dislodged something on the internals :S some times i can get ti to load to the windows is loading part then it shuts off all the fans work fine u can hear them running