The problem could lie in the chipping of your PS2 or the laser configuration in your PS2.
Problems can arise with the fitting of the chip as there are loads of wires to solder and the points are difficult to solder to.
Best thing to do is get your laser in the PS2 re-aligned, if that is the problem this will solve it, if not you will know it is in the chipping, then the best thing to do is get your chipper to look over it and check everything is OK.
What version PS2 are you using?
Sim
