Why is Sony a57 camera's EVF showing everything in Blue color?

My camera was lying in the bag unused for the past few months. Now when I took it out to shoot some pictures, I was shocked to see a strange issue with its EVF. Whenever I try to see through my Sony a57 Electronic Viewfinder, everything is displayed in Bluish color and the EVF seems to flicker a lot.

The same problem occurred a year ago and then Sony Service ppl had fixed the problem by doing some kind of repairing on it. But now the same problem has returned to haunt me.