Toughbook cf-53, trouble with LCD

[labtopia]

i have a toughbook i've been getting up and running on 10.8.4.  i have everything working but the onboard LCD, it uses intel 3000.  it goes blank after the apple logo.  only the HDMI at that point shows a display.  if i use HDMI its all fine but the LCD is not recognized and cannot be detected.  i've seen posts about changing a value with hex fiend in AppleIntelSNBGGraphicsFB.kext but that produced an unbootable system.

 

i can find no dsdt for this model and dont know what else to try now.

 

any help with this would be apprecieated.

 

dave