USB laptop supply

Help anyone,
I accidentally supplied my laptop "packard bell F0445-U-078 easynote" usb port with 12v supply the laptop wont start i removed the casing and find a burnt IC i think it's a voltage regulator only i cant see the part no.!!! but its an 8 pin soic pin 1,4 is ground, pin 2,3 are tied, pin 6,7,8 are all tied as 5v output supply to USB, i can't trace what pin 5 does, does anybody have idea what type of chip is this?

Yours Truly,
Ryan

I hate to say this, but if that one chip is a local USB regulator, it shouldn't stop the computer dead. It sounds like there is more extensive damage. Is there no start up mesage at all? You might want to take this discussion to the off topic area.