A guide on how to replace the logic board in the LG VX5400.
Turn off the cell phone and turn it over on its back side
Hold the phone case in your palm and slide the back cover towards yourself using your thumb
Slide a tool or finger into the notch at the top of the battery to carefully remove it.
Take the Philips screwdriver and unscrew the four visible screws on the backside of the phone indicated by the four red circles.
Then, take the pointed end of a spudger and pry out the rubber stopper to reveal the last screw at the top indicated with the blue circle.
While the phone is open and faced up, carefully insert a tool into the middle to seperate the bottom half of the phone.
Carefully slide out the keypad and remove the logic board. Then insert new the logic board.