The problem with the DUALSHOCK 3 gamepad

I have this problem: every 1.5-2 years I begin to fail the joystick (the buttons are pressed, the problem with the left stick, some buttons stop working, etc.). You don't know why this happens and how to fight it? I have salablanca to change the joystick for a new one. Here's how a month ago I flew again the joystick. You can still play on the ps3.