I have nearly the same issue as this other queston on my Dell inspiron 11 3147, running Ubuntu 14.04 LTS.

The touchpad works when I first login, if I logout and log back in it still works however when I close the screen and open it again then the touchpad is disabled and the mouse is invisible.

The touchscreen and keyboard are unaffected.

The modprobe -r psmouse and then modprobe psmouse fix does not work, neither does solution 1 given here or the fix given here.

Any suggestions would be greatly appreciated.

When working (output shown below) after closing screen and opening again, the Synaptics Touchpad is no longer visible in the xinput list.

amp@ashesashesallfalldown:~$ xinput list 

⎡ Virtual core pointer id=2 [master pointer (3)] ⎜

↳ Virtual core XTEST pointer id=4 [slave pointer (2)] 

⎜ ↳ ELAN Touchscreen id=12 [slave pointer (2)] ⎜

↳ DLL064D:00 06CB:2985 id=13 [slave pointer (2)] ⎜

↳ SynPS/2 Synaptics TouchPad id=15 [slave pointer (2)] 

⎣ Virtual core keyboard id=3 [master keyboard (2)] 

 ↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]

 ↳ Power Button id=6 [slave keyboard (3)] 

 ↳ Video Bus id=7 [slave keyboard (3)] 

 ↳ Video Bus id=8 [slave keyboard (3)] 

 ↳ Power Button id=9 [slave keyboard (3)]

 ↳ Sleep Button id=10 [slave keyboard (3)] 

 ↳ Integrated_Webcam_HD id=11 [slave keyboard (3)] 

 ↳ AT Translated Set 2 keyboard id=14 [slave keyboard (3)] 

 ↳ Dell WMI hotkeys id=16 [slave keyboard (3)]