Firmware Update Necessary
The first step when you're attempting to diagnose any type of peripheral hardware problem is to make sure that the product's firmware, drivers and software are updated. Firmware occasionally adds functionality to hardware, but most often it fixes hardware bugs that are discovered by consumers using hardware in unexpected configurations.
Unsupported by OS
The Logitech Rumblepad series is supported only by Windows operating systems, including Windows 98, 2000, Me, XP, Vista and 7, with operating systems older than XP. Linux and Mac operating systems are unofficially supported by third-party, generic USB drivers. Therefore, Logitech cannot ensure that a secondary function like rumble will work.
Unsupported by Game
Many games, particularly older ones, don't support rumble. Even if they do, it predates the standardization of vibrating controller technology in Microsoft's DirectX package. Even with updated DirectX software, some games can only be rumble-activated through third-party software.
Malfunctioning Gamepad
Finally, your gamepad may simply not be functioning properly. It's important to note that the vibration function is created by electronically actuated moving parts within the controller, which can malfunction or be disabled without affecting other parts of the controller.