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In sets that show the dot or line at shut down, it's OK, or the manufacturer would have had to do something to prevent eating a lot of burned picture tubes. I saw this happen at Motorola on one early model of ttansistor B&W chassis. I can't remember the exact cause, but if you turned it off with the on-off switch, the tube was discharged enough before the raster shrank.. HOWEVER, the first factory run had the last person on the line pulling the line cord, and the video drive would go to cutoff immediately, with a spot appearing and burning the tube a long time after. Well, they were pulling the plug, putting the set in the box, and the burn would happen when the set was out of sight. When the box was opened, there was a burned tube! They had to put in a zener that pulled down the video drive as soon as the B+ died, causing a bright flash as the raster was collapsing but not yet down to a dot.
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