I keep getting a black screen, then light blue then normal, this a sign of death? Would be great if I could have some expert help as I'm gonna request a service tommorow from HP/Currys.

It looks probable, but don't hold me to it, in all honesty, its a hard diagnosis to give over a forum so I wouldn't expect any firm answers from anyone. Personally, before replacing it, I would try removing it and re-fitting it as this has solved problems for myself before.

First check your drivers, if they are cool then try to look for the temperatures your gpu is getting, and if that is below riskzone then its probably just passin away slowly, would get rma request for it.

Sorry for the 2 week bump

Graphics is usually around 70-100'c (Badly cooled laptop-DO NOT BUY)

It does seem to do it more if I'm really going at it in a graphics sense...