Quote:
Originally Posted by init4fun
Vortelexfan, the TV your interested in is NOT displaying the classic trapezoidal raster associated with a shorted yoke, it is displaying the symptom of a badly failed vertical deflection circuit. To have a trapezoidal raster you must first HAVE a raster(a fully lit CRT screen) which that TV does not have due to the failed vertical circuit. Once the TV is displaying a proper raster only then can things like a trapezoidal raster be seen. If, after the vertical deflection is restored you end up with a pie shaped picture then you can go with the presumption of a shorted yoke, but at least get a fully lit screen before you go buying any yokes  |
My guess is that (from my previous experience with older TVs like this that i've worked on so far which is 2 TVs that I've successfully repaired/restored, and one that I gave up on and passed onto another member who lives locally) maybe a bad vertical output tube or some bad caps in the vertical stage, the reason why I suspect a bad vertical output/oscillator tube is because two of the 3 TVs I've worked on so far (a Philco Townhouse TV from 1962 and an RCA TV from the same time period) both had failed vertical deflection and they both used the same Vertical Output tube which is a 6DR7 Tube and in both of those sets that tube failed (and from what I've read, that tube is notorious for failing prematurely because it was driven hard in those TVs, and also because it wasn't a well designed tube to begin with.)