Alienware M17x R4 - Problems with starting up

Hello everyone!

I would like to share share my problem and and hope that someone could help me to recognize a reason of my laptop's fault.

I have a Dell Alienware M17x R4 (Intel Core i7 3740QM, 2.7, 16 RAM, 750 HDD, 128 SSD, nVidia GeForce GTX 680M - 2048 , DVD-RW, Windows 8, [m17x-0056]). I bought it almost one year ago, in April 2013.  Durinig the warranty period there was no any problem. I was so happy!!!

But couple months ago I faced to some unexpected problems related to discrete video card (Nvidia 680m). It was no detected in Windows Device Manager even in BIOS - only several reboots with option "changing internal video card to discrete"  helped to resolve this problem.  So, I decided to update a BIOS to A13 version.   After that the problem disappeared but not for a long time.

One week ago I received a warning message from Windows that OS has found some critical problems and has to be restart and recover. (during that my laptop was restarting several times)

After that Nvidia 680m was gone from Device Manager and BIOS.  I did the same as before.

Situation changed and Nvidia 680m started to be recognize as a "basic video adapter". I didn't succeed to install  Nvidia drivers, so I thought that was a software problem and re-installed Windows . But it didn't help also. After some manipulation with driver Nvidia Card started to be recognized as "3d video accelerator" (In BIOS it was still indicated as Nvidia 680m GTX). Some days after Nvidia card was gone from BIOS and only integrated graphic was detected.    

I removed the card from laptop supposing that it was dead.  Laptop was working during one day without Nvidia card,  

But Two days ago the laptop was fault to start up. Right now there is only black screen, fan stars to rotate for awhile, laptop restarts automatically several times after that power is switched-off. Also there are no any diagnostic beeps. 

I don't have the idea what is exactly wrong with laptop. Early I thought that it was a Nvidia card problem, now it seems that reason is a motherboard itself or chipset.

Please advice with this situation. Anyway I will bring my laptop to the service center but before I would like to know does somebody have the same problems and how much do I have I to pay to recover it 

Thanks in advance for answers