COMPAQ PRESARIO MAJOR PROBLEM , PLEASE HELP

Hello

I bought this Compaq Presario 1500 off ebay with problems it freezes when touched, hmmm... so i figured ok thats just a hard drive problem I recieved it from UPS and changed the hard drive installed Win Xp and entered the desktop everythings fine I lift the darn thing off the table boom it freezes im like ok Next possible thing RAM i checked ram bought new ram put installed it ran it again same thing plucked it and it froze.

After a whole night of opening it and checking things i checked the fans they where on nothing was above 48?c. I took it apart once again this time all the way and cleaned the surface of the laptop where the motherboard rested checked for debris from anything put it back toghether and ran windows again ran a movie picked it up !yay! it did freeze i shook it !yay! still going i close the Movie window FREEZES im like wtf. I reinstall windows get into the desktop same problem ok its not a software problem checked hard drive connections all FINE. So now i seriously do not know what the problem is its cause by movement so it has to be something wrong with the case.

Its so sensative i droped a quarter from about 1 foot in the air onto the desk it was on and it FROZE.

Things Ive Tried:

-New Hard Drive
-New Ram
-Disassembled cleaned and reassembled the laptop

IT FREEZES LESS NOW BUT IF I TAP THE RIGHT SIDE OF THE LAPTOP FOR GET ABOUT IT. ALSO IF I MOVE THE LAPTOP THE SCREEN DIMMS.

Thank you in advance for any help.
-jay