Ubuntu LTS 14.04 screen goes black and restores after log out or restart.

[Ami___]

I am using Ubuntu LTS 14.04. Recently, my Compaq presario v6000 laptop's screen intermittently goes black. I noticed it is still on but very dim to read anything. I thought it to be an lcd issue. But strangely, it restores immediately if I log out or restart. Any idea?

 

[Dave8671]

Check the battery power management settings. Most of the time e it is set to dim the screen if on battery.