Sudden screen crash

[Zafarjon]

My monitor sometimes starts to blink suddenly not showing anything except different colours and after a few seconds PC automatically shuts down.
It happened 2-3 times and has not repeated since then.
How can I check my monitor's health?
How can I know if it is hardware or software problem without using another monitor? I have checked cables: they are OK.
monitor - FLATRON ez T710BH (it is 11 years old so I have reasons for suspecting him !)
system - Ubuntu 14.04 (It happened after some time when I updated drivers xorg-video-intel )
no graphics card except built-in one for Intel Celeron processor.

 

[Coolboy951]

download this http://www.iobit.com/advancedsystemcareper.html
set it up and check every box and click scan after wards turn the pc off and turn it back on after 5 minutes

your problem is due to registry errors fragments this application will fix all of those problems