Hi Ishu.Sharma.Darkaura,

Thank you for the detailed description of the issue.

May I know if you have tried connecting an external monitor to the laptop? If you have not tried it, please connect an external monitor and check if the display is fine.

If the external monitor displays video without issues, LCD has to be replaced. If the issue occurs on the external monitor as well, the motherboard has to be replaced.

Please refer the following link to check the computer’s warranty status: http://dell.to/10pMa86

If the computer has active warranty, please send me the service tag and registered owner’s name on the computer in a Private Message. To send me a Private Message, click my User name, and then click Start Conversation.

If the warranty on the computer has expired, you may contact our expired warranty services to purchase/replace the compatible parts. Please refer the following link that has contact details for our Expired Warranty Services: http://dell.to/14FoBtb

Well, i don't have a warranty... And i cannot buy a new lcd at the moment... And i noticed that the lcd is working fine while normal operation- like browsing n watching movies... N its just the backlight turning off... I can see the display with a flashlight on the screen.. Also the backlight does turn back on in a few seconds or a few minutes and it only happens when i try to play a game... N  i am talking heavy games like assassin creed... It doesnt matter whichever game... Could it be a software problem or the windows 8 itself as my hardware is not officially supported by dell for win 8, like drivers... I have unofficial ones...

Hi Ishu.Sharma.Darkaura,

Issue is most likely hardware related. Do you have an external monitor? If you connect external monitor when the issue occurs, we can isolate the failure.

I dont have an external monitor... I'll have to arrange one...

Hi Ishu.Sharma.Darkaura,

Sure. Please check and let me know the outcome after testing with an external monitor.

Radeon 4XXX Drivers are not applicable to the latest Catalyst Drivers due to the HD4XXX series being Legacy and not supporting Directx 11.  Catalyst 12.6 is the last driver available.

 The June 2010 Directx 9,10 patch is Recommended along with the catalyst Legacy Drivers.

www.microsoft.com/.../details.aspx

The AMD Catalyst 12.6 beta driver for the AMD Radeon HD 4000, AMD Radeon HD 3000, and AMD Radeon HD 2000 Series is designed to resolve and minimize the occurrence of system crashes.

Note: The In-the-box AMD graphics driver that is included with Windows® 8 will include support for the AMD Radeon HD 4000, 3000, and 2000 series, and it will support the WDDM 1.1 driver level features. Please also note there will be no support for AMD PowerXpress™ feature on the mobility variants.

The AMD Catalyst driver for Windows 8 will only include support for WDDM 1.2 support products (AMD Radeon HD 5000 and later), and will not support the AMD Radeon HD 4000, HD 3000, and HD 2000 series.

Instructions:
 
Download and install the Driver from the following location:

• AMD Catalyst 12.6 Beta Driver for Windows® 7 and Windows Vista® 64-bit Edition
• AMD Catalyst 12.6 Beta Driver for Windows 7 and Windows Vista 32-bit Edition
• AMD Catalyst 12.6 Beta Driver for Windows XP 64-bit Edition 
• AMD Catalyst 12.6 Beta Driver for Windows XP 32-bit Edition 
• AMD Catalyst 12.6 Beta Driver for Linux® x86 and Linux x86_64

For detailed instructions on how to install the drivers, please refer to:

• Article GPU-33 for a Windows 7 based system
• Article GPU-1 for a Windows Vista based system
• Article GPU-2 for a Windows XP

Note! This Driver is provided “AS IS” and under the terms and conditions of the End User License Agreement provided
therewith.

Applicable Products:

This article applies to the following configuration(s):

Hardware:

• AMD Radeon HD 4000 Series PCIe
• AMD Radeon HD 3000 Series PCIe
• AMD Radeon HD 2000 Series PCIe
• AMD Mobility Radeon™ HD 4000 Series
• AMD Mobility Radeon HD 3000 Series
• AMD Mobility Radeon HD 2000 Series 

Operating Systems:

• Windows 7 64-bit Edition
• Windows 7 32-bit Edition
• Windows Vista 64-bit Edition
• Windows Vista 32-bit Edition
• Windows XP 64-bit Edition
• Windows XP 32-bit Edition
• Linux x86_64
• Linux x86

The external display did work when the lcd backlight was off.... And its strange that it still properly works unless i play a game....

Thanx... I will try that!!

Well, so much for all that trouble... After a long span of hit and trial troubleshooting... Not getting what is the problem.  I even installed new win 7 to get the lroper drivers... The problem still persisted... Still backlight failin with gpu extensive tasks more or less games only as furmark could take the gpu temp beyond 90°c , backlight never failed in that... I just stumbled upon something like stuck lid close switch and a stuck keyboard key on the internet- some reasons for the backlight others had... And one person  had shorted circuit element for keyboard... Did not know he was talkin about backlight of his screen or keyboard... So i just had strange thought like maybe an element has shorted in my keyboard or its circuit that causing somehow tappin of the brightness..

So, I just went into the bios n changed the function key behaviour from multimedia to function...

And the backlight hasn't gone off ever since... I've played a game for 4 hrs continuous to do a strain test...

So i guess m good to go...

Hey, "dell techs" can u give a reason for this... u ppl know the circuitry...