Quote:
Originally Posted by jhalphen
Hi to all,
@Kf4rca, we had several of these Broadcast quality Barco 21"/51cm monitors in the Video Lab at the Ampex facility in France.
We found out the hard way that the flybacks would fail if the monitor was not run with an active video or black burst sync signal present at all times.
This advice was given to us by the Barco Service dept after sending several units for repair.
Apparently the un-synced line oscillator would creep up in frequency and go into some form of runaway which in turn destroyed the flyback.
Best Regards
jhalphen
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I would think the problem more likely was the oscillator running too slow, so the peak (and average) sweep current got too high due to the horizontal output on-time being too long. The first IBM PC color monitors had a similar problem, dying if operated without sync. Those of us in the TV industry pointed and smirked at the IBM design. I'm surprised Barco would make such a mistake. They must have been close to the edge of overheating and/or exceeding the safe area of the simultaneous voltage and current of the output device.