I am sorry to hear you are experiencing this issue. I would suggest backing up all user data and performing a complete restore using Samsung recovery solutions. If the issue continues after this process then service will be required.
The touchpad stopped working after a small fall. I tried reinstalling the driver and doing a system restore but both of these failed, even after numerous attempts. An external mouse doesn't work either. I thought it must be a hardware problem but then when I went into system recovery from the boot menu the mouse worked! Any further suggestions?