[Central-Electronics] Problem with monitor scope on 200V - Help

[dave plowman]

My 200V works beautifully but recently the monitor scope which always produced a nice clean trapezoid is now all distorted, a friend called it a bloom, it no longer looks like a trapezoid pattern.
He said it sounded like I might have lost high voltage to the tube.
The trace is still nice and bright.
Any suggestions on where to start on repairs would be greatly appreciated.

Incidentally, I still have the cabinet for the MM-1 or MM-2 for sale, make offer, nice condition.
Thanks
Dave
W4PBU