Mine's the original G4 500. No problem with external monitor.<br><br>I'm betting that if you call Apple tech support they'll tell you to format drive and reinstall the OS. Painful.<br><br>I'd bet it's (50-50) bad (or damaged) OS software or bad port on your new PB. If latter they won't let you return for repairs until former is eliminated.<br><br>Bad OS install on a brand new Mac not possible? Been there and done that. :(<br><br>No win either way.<br><br>Good luck.<br><br>