dell flat panel monitor problem

i have a dell flat panel monitor....and after returning and trying to get it out of powersave mode, the light turned green yet nothing came up on my screen....i checked all the connections but everything was connected and the monitor still did not respond....when trying to restart my computer the monitor light flickered green then turned to green....it does not even go to power save mode anymore....just a blank screen and a green light....can somebody help????