monitor flicker - severe

have a LCD Samsung, 18 months old - suddenly developed intermitent flicker whole screen has very severe flickering lasts for about a minute at a time then is gone. there is nothing running, all cables are secure, running on a 2 year old HP media center w XP Pro, refresh rate set at 60 fastest it goes
what is going on, do I need new monitor?
thanks

 

Simplest way is to test. It is either your monitor or video card.
Attach problem LCD Samsung monitor to a different computer.
If LCD monitor works good ...
Attach a different monitor to your 2 year old HP media center w XP Pro. If substitute monitor fails, video card on your computer needs to be replaced. Their is a very slim chance it could be your monitor signal cable you have attached to LCD. The only way to test is substitute a known good cable. My money is on the monitor. 18 months old ... any warranty coverage??