I have a Gateway P-6831FX Laptop with Vista Ultimate. The Laptop LCD will sometimes not come on after I reboot the computer. I don't even close the lid and it happens. It isn't dim, it doesn't come on at all. No posting of CMOS (BIOS), nothing.

Please note... this happens sometimes, not every time. Frustrating!

When plugged into an external monitor, which works fine, Vista display properties can't even "sense" the laptop LCD. I try to enable the laptop LCD for dual display, turning on the laptop LCD, and it does nothing. It's like the laptop LCD is not even there.

Manually taking a magnet in my hand to the laptop lid sensing switch (the sensor that turns off display/sleep mode when you close lid), sometimes causes the LCD backlight to "turn on" but not display any images. By "turn on" I mean I can see the screen backlight turn on to a 'dark gray' screen instead of pitch black. Subsequent reboot the laptop display is not working again!

Here are the facts:

• Only happens at random and only after a reboot. Waking from Sleep mode isn't a problem.
• Pressing F4 function key for dual display does nothing when this happens.
• Closing lid doesn't seem to be related. (unless it is only after reboot.)
• using external magnet from laptop screen sensor sometimes triggers backlight to turn on but reboot back to square one with no LCD display.
• an external display always works fine.
• I have taken apart LCD, checked all wires and ribbons for loose connections or damage.
• I have replaced the Inverter.
• It doesn't seem to be heat related as I can put in sleep mode and resume fine when very hot. (external monitor works fine too).
• Sometimes the screen works fine as if there is not a problem at all. Even after a reboot... This is random.

Any ideas out there? If it is a bad part... which one? The LCD seems to be fine. What are the odds of 2 bad inverters? The backlight is fine. The LCD wires/ribbons seem to be fine.

I am at a loss. No warranty left and Gateway tech support is clueless. Thanks for any feedback that might help.