# Laptop screen turns off



## Ferkhat (Aug 12, 2010)

Hello! Im having an issue with my laptop. For 2 days now the screen doesnt work. When i close the lid and open it up again, it turns on for 2 seconds and then turns off. I looked really close to it and i could see my windows in it but there is not light. Im currently using the laptop by connecting it to the monitor and it works just fine. 

Here is info about my laptop:

Gateway P6831-FX
Windows Vista 32bit
NVIDIA GeForce 8800M GTS


If you need more specific info, just tell me. Help would really be appreciated. Thank you.


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## Kharm (Jan 24, 2010)

Your inverter or backlight is out. If you see that the back light is red before it goes out then its definiately your backlight. The only way to narrow it down outside of that is to have a test inverter or lcd. If your not comfortible ordering parts (such as an inverter) and installing them, then you should send it in for repair.


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## Ferkhat (Aug 12, 2010)

So if the backlight is out, then i think it would not turn on at all but it works for 3 seconds and then turns back off. And i dont see any red light when its about to turn off.


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## Kharm (Jan 24, 2010)

Yea if you have no backlight, but you see an image on the screen when you look hard, then well you have a backlight issue. It coming on for a couple of seconds when you flip the lid switch or turn it on is not uncommon. I will give you this, it is more likely it is the inverter than the lcd FL tube b/c you dont see red light before it goes out. 

Here is the part number 8016847R


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## Ferkhat (Aug 12, 2010)

Ok this is so weird. I bought the inverter, exactly that one and it still shuts off.


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## Kharm (Jan 24, 2010)

That sucks. It must be your FL tube then. That means replacing your lcd. Backlight issues can be hard to diag b/c there are many possiblities such as: inverter, lcd fl tube, lcd cable, lcd connetor on the system board, and blown components on the board. However usually when the backlight works then goes out its either the inverter or the FL tube. 

You can order a lcd (keep your inverter for test before you return it, if you can) or you can just send it in for repair.










GATEWAY / Displays LCD Glass Only
GWY DP 17.0" WXGA+ LCD ONLY 
part number is 2528381R another part number would be simply LTN170X2-L02

its about $162 for exchange (i.e. you send your bad lcd back to them so they can refurb it). I got that price from mpdparts.com


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## Judith1974 (Jun 29, 2011)

I have been having the same issue. It is not a hardware problem. It seems to be a driver problem. I reinstalled the driver and it still has problems but each file it asks for it gets better until... I got an error message:

igfxtray.exe - Entry Point Not Found
The procedure entry point GetCurrentDisplay could not be located in the dynamic link library hccutils.DLL
Now it seems to be a registry error. 

On start up, when it reaches the log on scren it sounds three long beeps. When I close the lid and re open it stays on for varying lengths of time but never more than a few seconds. The problem originally started when I get infected. I removed the infection, which damaged my operating system and made it hae annoying glitches. I used XP disk to repair. Ever since the repair the 3 beeps started. Then it would occasionally shut off. It got progressively worse. The only thing that makes it at all better has been driver reinstalls. Now that I have this new error message it will not stay on for more than a few seconds.

I am hoping that the person that originally posted will see this & let me know if they came up with a long term solution.


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## Judith1974 (Jun 29, 2011)

SOLUTION: Worked for me. 
I went into the Device Managr & uninstalled the Display Adapters. Upon restart the Add Hardware Wizard came on and reinstalled everything. It was missing a few files that I downloaded from www.driverguide.com 
Everything works again. 

I realize that the poor guy that was having the problem in the first place probably has solved it by now, but hopefully this solution will help the next guy having the same problem.


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## Kharm (Jan 24, 2010)

Judith1974 said:


> SOLUTION: Worked for me.
> I went into the Device Managr & uninstalled the Display Adapters. Upon restart the Add Hardware Wizard came on and reinstalled everything. It was missing a few files that I downloaded from www.driverguide.com
> Everything works again.
> 
> I realize that the poor guy that was having the problem in the first place probably has solved it by now, but hopefully this solution will help the next guy having the same problem.


I doubt you're having the same problem. He was losing back light, yet he could seen the image on the screen. Doesn't matter if you're in windows or not. You can be in the bios and experience this. Just by coincidence I have one right in front of me with this exact issue that I'm about to diagnose.


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## Kharm (Jan 24, 2010)

Here it is with flash









and with out flash 










both in the bios.


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## Judith1974 (Jun 29, 2011)

I was losing back light, yet I could see the image on the screen. It didn't matter if I was in windows or not. 
Just recently I updated the driver again and started experiencing the same problem again. I was hoping for new information by now, but still my only solution was to roll back the drivers. 
This is a very annoying problem. I can push the button to fool the computer into believing that I have closed and reopened the laptop. The screen will come back on full brightness and then, varying lengths of time later, blink back out. If I shine a light on the screen I can see the image on the screen and everything continues running. If I continue pushing this button repeatedly it will occasionally stay on for a whole minute... then goes super dim again. 
My research on this over the last few months is telling me that it is a Registry Error. I have found no way to completely solve it as of yet, rolling back the driver only semi-solves the problem. It seems to get confused again if I run on battery power then plug it back in again. Then I deal with it blipping out a few times before it stops.


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## Kharm (Jan 24, 2010)

Judith1974 said:


> I was losing back light, yet I could see the image on the screen. It didn't matter if I was in windows or not.
> Just recently I updated the driver again and started experiencing the same problem again. I was hoping for new information by now, but still my only solution was to roll back the drivers.
> This is a very annoying problem. I can push the button to fool the computer into believing that I have closed and reopened the laptop. The screen will come back on full brightness and then, varying lengths of time later, blink back out. If I shine a light on the screen I can see the image on the screen and everything continues running. If I continue pushing this button repeatedly it will occasionally stay on for a whole minute... then goes super dim again.
> My research on this over the last few months is telling me that it is a Registry Error. I have found no way to completely solve it as of yet, rolling back the driver only semi-solves the problem. It seems to get confused again if I run on battery power then plug it back in again. Then I deal with it blipping out a few times before it stops.


if "It didn't matter if I was in windows or not", then why would drivers in windows or anything to do with the registry have anything to do with your back light issue?

I think you are correlating software drivers to the back light issue when in fact it has nothing to do with the issue. Its difficult to diagnose back light issues when you don't have known working hardware such as: lcd, lcd cable, and inverter. When you don't have the proper tools its easy to fall into common psychological pitfalls because of that. For example _Ad hoc ergo propter hoc_ meaning "after it, therefore because of it." Confirmation bias is another where you tend to count the hits and ignore the misses. In this case the misses being the back light not working despite rolling back the driver.

Do you have the same Gateway that this guy that started this thread has? Gateway P6831-FX

Regardless you can prove to yourself its not a software issue at all by running the computer in the bios and seeing if it still loses back light. It if does lose back light regardless whether if you're in Windows or not - like you said. Then you know it must be a hardware issue. Frankly I have been doing laptop repair for way too long (about 8 years) and the only time where I have seen software cause a lcd to lose back light was recently actually, in a very specific situation. Some of the newer Acer laptops lose back light when booting into clonezilla - Thats it! That the only time I have ever seen software cause the backlight to go out. In ever other cause its _always_ a hardware issue.

The reason the back light comes back on when you hit your lid switch is because the inverter sends a spike of voltage to the FL tube (which is in the lcd) to get it started. Usually when you can do that to get the back light to work again for a little while you know its a bad FL tube. There is a chance that it is your inverter, but I would say 9 times out of 10 in that situation its your lcd. Also if you see the back light giving any kinds of faint red to pink light then you know for sure its bad and needs to be replaced.


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## jazzCFI (May 8, 2012)

This is the oddest issue. I've also been repairing laptops for the last 9+ years and I've recently encountered this issue on a friends laptop. In this case I went ahead and first tried replacing the inverter, then the lcd. I even tried replacing the cable and I'm still getting no backlight.


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## wiiztec (Mar 1, 2014)

I am having the same problem with my laptop; an IBM Thinkpad T60, I first noticed the red hue a week or so before the first screen blackout. When the screen would come on it would have a red hue to it before it would correct itself in a second or two. I figured out a solution that seems to prevent the blackouts and that is to set my screen brightness 2 levels lower than maximum. I would like to know how long I can expect this to work before I have to set it lower or eventually get the FL tube replaced

I don't know why this post was moved into it's own topic but please keep it here it's dependent on the information posted in this thread


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## roodap (Mar 2, 2012)

why nobody has thought about the blanking circuit error [display hardware] 
probably a capacitor or some other type of timing circuit external to the display driver chip


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## wiiztec (Mar 1, 2014)

Well If red hue indicates a failing FL tube than I definitely have an indicator of that


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