The first thing you should do to verify that you do not have a bad gun is to use the test menu and attempt to calibrate both guns. To do this, first press the self test button in the game or the slide switch on the PCB (labeled test switch) to get the game into self test mode. If your guns don’t work, then you can use the player one and player 2 start buttons to navigate to the gun test and then follow the on screen instructions. When you have a bad IC, the gun usually will shoot above and to the right of the target. You can always switch guns and see if the problem follows the gun or not.
If you are not very experienced with surface mount technology, then do not attempt to remove and solder this IC or you could possibly damage the board beyond repair. If done incorrectly, this could cost you much more than it would to send it to a professional for repair.