amp draw of lcd screen?

Hey there guys and gals... Ihave a Soundstream LCD-TFT VHR-76 headrest monitor... I was wondering how many milliamps approximately does it pull? I want to run it in my dorm room andi bought a 120volt to 12 volt converter, but it is only 600 milliamps.... I can't get the screen to turn on and it did just fine in my truck, thats why i'm thinking i dont have enough power going to it... Thanks for any help you may have, or guesses if it draws more than 600 milliamps...

You can test the current draw with a multi-meter. You first have to make sure the leads are connected to the terminals the meter uses for the current setting. Secondly, wire the meter in series with the screen, connect power, and turn on the screen. If your meter has a hold function you may even be able to capture the peak current the monitor draws as its initially turned on. You should easily be able to measure the continuous current the screen draws as well.