Alienware M17X-R4 Video Card Problem 680M

Hello guys,

I send my PC to offical service at this summer for a completely different issue (keyboard issue) and after it came back from the service I have started having this quite frustrating issue with my pc which I cannot resolve about 3-4 months. While gaming I get this sudden freeze following a blink at screen. After the black screen Windows prompts an error message which says like "Video card stopped responding and has succesfully recovered." And effects are not always the same. Sometimes black screen doesn't go away until I close and reopen my lit. And sometimes black screen becomes light blue even orange screen and doesnt go away at all. Sometimes it causes a lot of exe programs(f.e. games, chrome, battle.net) to crash and sometimes doesn't. Also a note, sound continues to come while these things happen. So if I'm in a skype call with someone I can keep talking. Lastly, sometimes PC completely freezes even sound stutters until I hard-reset the pc.

Recently these crashes started to happen very often. Especially when I'm playing WoW. 

Things I have tried:

- Cleaning inside of my laptop and fans.

- Returning to older version of Nvidia drivers & and making a clean install.

- Returning to Windows 7 from Windows 10.

So I'm quite sure that this is not an software problem. It has to be a hardware fail.

Things I have noticed:

- When this blinks happen GPU usage goes to %0.

- I never get this issue while I'm only on battery. But I get like unplayable 20-30 fps which is normal on battery.

Also another funny thing is after my pc came back from service It cannot detect my integrated graphics card which is Intel HD Graphics 4000. It says -Not detected- on BIOS and I cannot install the driver because installer gives an error message like"This pc cannot meet requirements.".

Other thing I tried was swapping and trying RAMs individually at different slots. No luck.

Today I found a forum thread which says it can possibly resolved by decreasing GPU Voltage / shader clock because motherboard sometimes cannot feed the video card with enough voltage. But I cannot underclock even change my video card's voltage and shader clock from any overclock tool. It's just grayed out and cannot be changed. I can only change GPU clock and Memory clock. This voltage thing makes sense to me because like I said I never get this issues while I'm only on battery. I learned that laptop automatically decreases GPU voltage when it's on only battery. Is there a way to change my video card's maximum voltage or not? 

Sorry If I wrote poorly I just tried to be as brief as I can be while giving as much as information I can. 

I'm in a very desperate position and out of options. If you have any idea or any information I'm waiting. Thanks.
 

Brief rig:
i7-3820QM CPU

Nvidia 680M GPU

32 GB RAM

Official Alienware Windows 7 version & drivers.