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Old 05-14-2020, 04:17 PM
Retroplayer Retroplayer is offline
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Join Date: Sep 2018
Posts: 6
Quote:
Originally Posted by MadMan View Post
Using a magnet might gauss the screen and make it worse. Of course it can be degaussed, but that's a process. I would say that turning the yoke a bit would correct this, but if you note that the left side of the numbers is a near-perfect vertical line, for whatever reason, the image is being skewed up on the right side. If you tried two different monitors and two different video sources, perhaps something else is amiss, like bad cables or interference. Try the video source on a known-good tv or monitor.
I have seriously considered that it must be getting pulled from somewhere else. I notice that these are very sensitive to static. When I put my fingers near the glass, the image moves almost like a plasma globe. Maybe some better shielding and more ground points would help.

One common thing on both displays is that the flyback transformer is right next to the neck on the left side (the side being pushed away).

Using the magnets in the right polarity, when I pull down the right top, it squares up perfectly (the magnets are near the yoke, not the glass.) I found with a magnetized screwdriver that there is a sweet spot on the yoke that if I rest the driver there, the image is nearly perfect geometry. It is down near the circuit board right about where the deflection IC is located.

I am going to try my experiment in some different locations in the house.

I have tried my video source (it's an Arduino with the TVOut library) on a 3" color LCD monitor and a Sony FD-10A and it seems to work fine on those. In the new fangled world, it would almost seem like the phase is off. But no such adjustment on these old sets.

I'll try manipulating the yoke and different locations. At least it is just a B&W set, so not much danger completely bodging the yoke alignment. Just need to be careful not to get myself zapped working in such a tight location. Thanks!

Last edited by Retroplayer; 05-14-2020 at 04:32 PM.
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