I have Toshiba l20 laptop with old intel celeron m 1.7ghz, 256 mb ram, integrated radeon express 200m,.... Screen is broken when I set on him couple of years ago. I connected it to lg 19 inch wide screen and it worked fine, until couple of days before.
When I play any movie in any video player it plays sound and subtitle but there is no video! Just black screen!
I even tried kmplayer becouse he has internal codecs but same phenomenon occures.