I thought I may have misunderstood what the OP wrote so I went back and read it again.





On an older laptop, they usually don't start with both the LCD and an external on 
at the same time, or if they do and an error occurs, the external will default to 
disabled/off.  I suspected this might be the case here if the external works on another 
computer.  Now, if the graphics adaptor has failed, then most of the time, the machine 
will not boot, but this depends on where the failure has occured in the video output 
chain.  Also, I have not worked on any portable that has two actual seperate video 
drivers installed.  Can't because it's only one graphics adaptor in this case.  Two 
monitor profiles(.pif files), yes, but that isn't a video driver.  The driver has 
been written to properly support the monitor(s) and graphics card options and IME, 
that is built-in to one driver.

IME, if you can't see anything on the screen using the flashlight method I described 
and any keystroke combo's that may enable the external monitor after Windows starts 
won't work, (or while in the BIOS) then you are right that the adaptor has probably 
failed and that usually means a replacement of the motherboard.

However, if you can see graphics on the screen by using an off angle source of light, 
it usually means a hardware issue of some type, possibly a bad backlight, or it's 
control circuitry.  Possible that's software, but have yet to see that IME.  I have 
however observed a bad BIOS flash disable the backlight on Dell portables though.

• Reply or follow-up to this message

• Search this forum
• Start a new thread on a different subject

• Report abuse of the forum