Blanking screens has happened before on the A320 in the 90's. That was due to an over zealous pilot inserting too many possible alternates and overloading the computer memory. It didn't happen to the rest of us because we were aware that it was a possibility and didn't push our luck.
It is also important to use common sense, even on an Airbus. The manual doesn't cover all fault scenarios as has already been mentioned. I remember an A320 having a wing tip brake come on where the ECAM assumed an assymetric flap condition. In fact the flap had locked at flap full but the ECAM instructed to put the flap switch to flap 3. This resulted in overcontrolling by the pilot and a difficult landing.
I had the same fault at my next simulator check. The flap on the controls page showed it was in full but amber. I landed normally with the switch at full and wondered what the problem was supposed to be. Only then was I told that what I was given was what had happened for real, but the crew had pedantically followed the ECAM message. Even my F/O in the simulator was trying to point out my incorrect procedure because I wasn't following the ECAM message.
It would seem that some would just follow the 'correct procedure' without using common sense even if there is no correct procedure for the actual condition present at the time or they have misdiagnosed the condition.