I've got a Dell E6400 laptop with Intel GMA 4500MHD integrated video driver running WinXP SP3 with the basic Dell dock, which has a DisplayPort and a DVI output.
- The DisplayPort output is hooked up to a 2560x1600 Dell 30" monitor (via a DP to duallink DVI converter, but I don't think that is relevant).
- The DVI output is hooked up to a Dell 20" 1600x1200 monitor.
Everything used to work fine. I'd go into standby, eject the laptop, and the laptop screen worked fine. When I'd redock it (with the lid closed), I could press the power button, and both external monitors would come on, at the right resolution, position, etc. This worked fine for months = hundreds of undocks/docks.
I went on vacation for a week, using my laptop off and on as I normally would (I wasn't messing with the graphics/drivers/etc - it was only email), and when I came back, the external monitors didn't display anything when the laptop was docked with the lid closed and I pressed the power button. The power button on the 30" did change from green (or yellow or something - I'm colorblind) to blue, indicating it was seeing a signal from the laptop, but the screen stayed black.
I finally found that if I opened the lid of the laptop I could get an image to display on the 30" - basically it's acting as if the 30" was an external monitor connected to an undocked laptop - pressing Fn F8 cycles through laptop-only, laptop+30", and 30"-only screens.
So I'm assuming some setting somewhere got hosed, but I haven't been able to change the behavior back (or at all) using XP's Display Properties or Intel's display utility.
Does anyone know where the display info is stored so I could examine it and/or reset it?