XPS L502x gives solid blue/green screen and turns off random

Dell XPS L502 x , purchased in 2011 december, Works perfect because only used for Home entertainment.
Service TAG <********> for privacy purpose
Memory: 8GB
Processor: Intel(R) Core (TM) i7-2670QM
                    CPU @ 2.2Ghz(Cores 4) [Logical / Core 2]
Nvidia GeForce GT 525M ( I think integrated )
Operating System: Microsoft Windows 7 Home Premium

I searched various discussions online but seems like no one can come up with the solution to this since 2011.

Please note that i installed factory image and this laptop still seems to sometime give blue/green screen randomly and not function. After turning it off and then on again, sometimes the fan makes huge noise but nothing works.

Even when i connect to external display like my 4 k TV it seems to freeze and all i see is blue screen or green screen.

Please advise any fix because i have ran every test and nothing shows up anywhere.

When its working its working perfectly fine but when i connect to external monitor it never functions properly , 1 hour or 2 hours later it shows solid green screen and then turns off.

I am not sure if its the processor or integrated graphic card or is there any way around this ?

Thanks !