Whenever I close the Laptop without locking/logging off, system goes unresponsive. Unresponsive in the sense it doesn't shows login prompt or not even some error message. However, there is no problem when I lock/log off system before closing the lid of my laptop. I am able to use the laptop only after removing and adding the battery to the slot(bad habit, still this is the solution I found). Even the force shutdown - long press of Power button is not working.
The issue happens irrespective of running applications.
One more thing I noticed is that LED indicator for hibernate is glowing as if the laptop is hibernating when in unresponsive state.
Ubuntu version : 14.04 Hardware : Dell Inspiron 3437
Please suggest some solution. Thanks.