Ok so it's now 13 years old but it's still not a bad projector (it works!) My Barco Data 600 (1989 vintage) has been popping a bit over the last couple of weeks. Onece it popped so loud I thought a tube might have blown (fortunately not) but it did throw the convergance way out (only vertical and horizontal global settings though). It did it again today with no detriment to the picture in any form. My initial thought was that it could have been a bit of phosphur falling of the front into the electron beam. But since all the tubes did it at the same time last time I guess it is not. Any ideas Gordon or Roland? Cheers!