eMacines g420 display stays black at start up

Hello.

I need some advice here.
When i power up my eMachines, the laptops built-in screen stays (almost) black.

First black, after a couple of seconds like a "backlight" or something is lit but the screen is still black.

Windows 7 Ultim. loads up OK.

When i plug in another monitor to the laptops VGA connector it works, i can use the machine,

but the laptops own screen stays black.

Sometimes, when connecting another monitor to it, back and forth, it suddenly begins to work ok with the laptops own display.

EDIT: A couple of times, opening and closing the laptop (moving the display) would make the image appear to the laptops own display. Maybe a loose connection, go figure, but it does not do the trick every time.

This problem started after installing Win7 SP1. Or Maybe that was just a coincidence.
Tried to roll back with system restore, starts working sometimes with that. Sometimes works with windows drivers for nVidia 9100mG. I dont have clue with this one anymore.

Does all this sound familiar to some of You? I would greatly appreciate assistance here. Than You in advance,

best regards

I.A.
Finland

P.S. Laptop equipped with Nvidia GeForce 9100m G, Windows 7 Ultimate 32 SP1.
Tried to install old and new drivers for nvidia, no use of them.

 

When you plug in an external monitor, right-click on "My Computer" and choose "Manage". Then on the left of the window choose "Device Manager" and expand the section in the centre called "Monitors".

Does your laptop display appear when it is blank?