unable to burn cds and dvds.

Hi guys, i sent my laptop off to get the my nividia chip replaced, and when it got returned i tried to burn a data dvd using itunes i get this error message 'the attempt to burn a disc failed. The device failed to calibrate the laser power level for this media.' I have also tried to burn dvds using toast titanium and other dvd burning software and keeping getting all sorts of error messages, any help or tips would be much appreciated lads hope i provided enough info thanks