Well, coincidentally the same thing started happening for my dads laptop today.
I've tried a lot of fixed but to not avail.
1) Tried to connect to external monitor
2) Swapped memory to other slot but for some reason it didn't fit in the alternative slot
3) Plugged off power and removed battery then held power button for 60 sec etc.
Nothing helped so far. If someone has tips then please, I could use them aswell.