Do a Google Groups search for Sony AKB, Sony blank video, etc.
Lots of prior postings. Odds are the picture tubes are too weak for
the AKB to properly compensate and it is putting the set into blanking
as soon as the video comes up and the cathode current rises.

Good chance the set needs all three picture tubes for a solid fix,
about $1000.

Sometimes a short term fix is to readjust the G2 voltages.

David

jim wrote:
Video cycles on and off- app 5 seconds on and 2 seconds off.service
info currently on order. Thought someone might have run into this B4.
Jim