(m17x r2) Screen turns black at specific times

When I turn on my laptop, the screen is black. Still starts up normal, just with no display. As soon as I lower and open the laptop, the screen turns on. It remains on, until I plug another display in (via hdmi). The screen then goes black again, while the external display functions properly. Doesn't make a difference if it's on extend or duplicate mode. Closing and opening the laptop lid does not turn the screen back on, unless I first unplug the hdmi.

Even with 100% fresh install of windows/linux, the screen is black on startup. No signs of issues with anything else. Games run fine. External dispalys work fine. Screen never goes black aside from on startup, when plugging something in, and reaching the login screen on linux. The screen remains black until I close/open the laptop.

This has been happening for over a year. In the past it's just been a minor annoyance, but now I must have both the laptop and an external display working. I have gone through a long list of things to try, and none have shown any results or errors. I have no idea what specs are relevant to provide for this issue (seeing as it happens at start-up on a 100% fresh install before even reaching the bios/boot option screen).

Here is a video of me plugging in my monitor (via hdmi). The install is 100% fresh aside from graphics card / wi fi drivers (and the problem occurs before installing them).
https://www.youtube.com/watch?v=d6KfEX0x9Xs

Everything I describe happens 100% of the time, and the screen never goes black at any other time. The laptop works fine in every other way.

 

Hi and welcome to NBR, :hi2:
A couple of things I would check.

1. Check your cable from lcd is firmly plugged into motherboard.
2. Check your windows/linux drivers when duplicating onto other screen. EDIT ** have a strong feeling your linux drivers are causing this issue**
3. What GPU are you using?

 

Thanks.

1. I took apart most of the laptop and checked every connection I could see. Everything seems to be connected correctly and firmly. If there are no other suggestions, I will take it apart again and look specifically at that connection again.
2. The issue happened before I ever installed linux. It happens off an entirely fresh install of windows. And it happens when booting linux from a flash drive with no other OS install on the computer. I think that eliminates any possibility of it being a driver issue? Maybe there is something I'm misunderstanding here?
3. 2x AMD Mobility Radeon HD 5870 in crossfire. As I said, even before installing the drivers, the issue is there. Turning crossfire on and off also has no effect.

 

I just held a flashlight up to the screen while it was black, turns out only the backlight is turning off. Movements are still visible on the screen when looking closely. I'm not sure what the next step is now though.

 

Perhaps the backlight of LCD screen is on it's way out, but yes major weirdness...
I would thoroughly check monitor cabling just to be sure.

Good luck.

 

Thanks for the advice. I had my uncle look at it. He says the problem is hmost likely to do with the inverter, otherwise there is an issue with the power supply. I'm not sure he's right, but the inverter is a cheap part, so I'm going to replace that and go on from there.

 

THe RGB LED in m17xr2 has no inverter so hypothesize something else....
My feeling is I wold disable the crossfire and try one video card at a time.
Good luck.

 

What screen do you have?
1440x900 2x CCFL
1920x1200 2x CCFL
1920x1200 RGBLED

It does sound as inverter issue to me if you are able to see movement with a flashlight...