no picture - movie window is black

Hi,

I have a cobbled-up Sony VIAO using an external Hitachi flat panel 
display.  The laptop's original display quit and has been romoved but I 
can't open bios to disable it or check its status. Ogle runs and I hear 
the DVD sound track, but the picture window is just black. The same 9.2 
Ogle distro works fine on my desktop with a similar Radeon 7500 graphics 
controller. I don't see anything obvious in XF86Config.

Thanks,
Steve McCampbell