I bought a new Dell M3800 laptop and it worked fine for three month.
One morning it refused booting. The Dell Windows Recovery CD will not load either Just goes to black screen.
I tried everything I could think of and everything I found on google with no luck.
Yesterday I removed the HD and connected it as an external drive changed the Boot options and it worked.
But it still will not boot when connected internally. The Dell diagnostic tool does not find any problems.

Dell M3800.
SSD 250GB drive.

Please help. What could be causing this?