Dear All,When trying to run the sim, pmdg 747, downloaded a week ago, assuming the latest version, the primary displays are all black, switched off. If selected during a flight, it is on for a minute, then off after that.Went through several tutorials, but the screens never turn on again !Any help is apprecited.Regards,

Uninstall the 744 and reinstall & patch, that should clean up the problem.