Why doesn't my screen display a video, What should i do if my screen is dark – Sony VAIO VPCF11 User Manual

VPCF119FX, VPCF114FX, VPCF11LFX, VPCF11GGX, VPCF116FX, VPCF11QFX, VPCF11KFX, VPCF111FX, VPCF11JFX, VPCF11CGX, VPCF119HX, VPCF113FX, VPCF11FGX, VPCF1190X, VPCF11EGX, VPCF112FX, VPCF11HGX, VPCF117FX, VPCF11NFX, VPCF11AFX, VPCF119GX, VPCF11BFX, VPCF11DGX, VPCF115FM, VPCF11MFX, VPCF11PFX