Trance88
11-11-2011, 10:26 AM
Hey guys,
I've got a 1991 13" Magnavox TV that has a slight bit of red ghosting in the top right quarter of the screen. The entire picture is also on a slight tilt. Is there any way I can manually adjust the position of the red so it's more in line with the other guns or is this a factory defect?:scratch2:
old_tv_nut
11-11-2011, 10:37 AM
Not familiar with this unit, so if someone is, they can override these general comments:
1) have you done convergence before? If so, I would open it up and see if there are any adjustments on the neck that aren't firmly glued in place.
2) errors in one quarter of the screen are the least likely to be fixed by adjustment - you can end up just chasing the error from one corner to another - but you might experiment placing small magnets on the bell of the tube
Eric H
11-11-2011, 01:45 PM
The tilt can be fixed by rotating the Yoke slightly, assuming it's not bonded to the CRT.
This might have some effect on the convergence but doubtful.
By ghosting do you mean the whole corner is slightly Red or do you mean the Red doesn't line up with the other colors, most noticeable on white objects.
kx250rider
11-11-2011, 02:41 PM
I would have to guess that the TV was dropped or banged, which caused a bend in the shadow mask inside the CRT. Very common on those later model CRT sets. All you can do, is as Eric says, loosen the yoke and tilt it to correct the tilt, but that may throw the convergence off worse, or if you're super-lucky, it could correct it. Don't mess with the adjustment rings on the yoke, as those are very tricky. The two closest to the front of the TV are purity, and the other two or four closer to the socket, are center convergence. The edge convergence is done with permanent magnets on the outer shell of the CRT, if needed. Usually those smaller sets don't require edge convergence, which is why I suspect physical damage. The edge convergence is also affected by putting small wedges between the yoke and the flare of the CRT, to cock it up/down and back/forth slightly. But that would not affect corner convergence; it affects the whole top and bottom edges, and whole left and right sides.
Charles
Trance88
11-12-2011, 06:41 PM
With loosening the yoke, do I have to take any major precautions when doing it?
Trance88
11-14-2011, 03:56 PM
Sweet! I didn't even have to loosen the yoke. I just grabbed the metal part at the base of the picture tube and turned it and it worked! I have a nice straight image now. I guess the convergence wasn't as bad as I originally thought it was and I'm finding that the picture overall is really good! I'll have to set this one up as a daily watcher once I get something to put it on.:thmbsp: