black screen at startup, windows starts, screen still black

Hi, I'm not sure if this is hardware or software, but the laptop in my sig has an intermittent startup problem - completely black screen, no backlight, no bios post, no cursor blink, but the leds are on and windows is starting, it plays the welcome chime to say the login screen is up, but its still black. The weird thing is, if I close the lid and sleep it at that point, then open it up again, it wakes with the screen on, but at a default (?) 1024x768 resolution, and cannot be reset to native res, can't add a custom res in Nvidia control panel, tried everything. The device monitor no longer shows a monitor. Tried new graphics drivers, still no good.

Then, other times, the screen stays black until the windows welcome chime plays, then the screen comes on, in native resolution, and the monitor then shows up in device monitor. When its like this it functions perfectly for weeks, sleeping rather than shutting off, with no other video/graphic errors at all. Then I need to do a reset after a couple of weeks, and its gone again.

The fact that I can't even see the bios post when it starts (I've tried shining a light on the screen too, nothing visible) suggests it must be hardware - what do you reckon?

 

If you can't see the BIOS, it's most likely hardware and from what you say, it sounds more like a problem with the display than the graphics card. Have you tried using an external monitor to check whether the display is the problem?

 

Might be some problem associated with dieing 8400M GS...

 

I can get a picture on an external monitor, and see the bios on that, so yeah, it must be the display itself I guess. I read somewhere about EDID? - the initial exchange between the display and the bios, and that might need checking, but I'm not sure how i'd do that. it seems like heading into dark arts down that route though - anyone know what EDID is about?

Edit: I posted this in Hardware initially, but I think a Mod moved it due to the win 7 black screen problem a few people had, but this isn't the same thing.

 

It may be the LCD Backlight damage.
If you see shadows on the black screen it is definitely that.
It can be either the inverter or simply a loose connection.

 

No shadows. And no warranty any more either.
oh well, maybe its time for a core i5? how terrible

Oh, and rather off topic (sorry padmé), thanks for the heads-up about ODMs weinter, I never knew. Compal of Taiwan is the biggest notebook manufacturer in the world. Number 2 is Quanta.

 

I'd say it's a loose connector somewhere...

 

Ok, I've got a screwdriver, I'm earthed, and I'm going in...

 

you can see if its the backlight by shining a flashlight or led light up at the screen and see if you can see faint colors. if not that it could be the inverter. if not that cable or connector. otherwise mobo