problem over-clocking my 480gtx

[Zairs]

Ive been over clocking my 480 gtx and all was going well with low temps so i got a bit over confident and upped it up from 910 to 950, then applied it and it white screened. how can i get a usable screen back to put the settings back down

 

[Zairs]

was hoping i wouldn't have to do that

How can i stop it happening in the future, or was it cause it was too big an increase??

 

[Zairs]

what temps do you get on them?