i rescued a color classic from the trash today on my block. i powered it up, and to my dismay, it has a failed analog board.
the convergence is off horizontally. (pretty badly actually). vertically the convergence looks perfect.
the adjustment on the back of the neck board has NO effect on the picture. the neck ring adjustments are still glued in place and havent moved, i tried to adjust the rings, and it wont pull the colors in far enough to converge them without distoring the vertical convergence. so i returned them back to stock positions to restore vertical convergence. horizontal convergence needs major correction.
only thing i can figure is the analog board uses a dynamic convergence correction circuit which has failed? anyone have a schematic of this monitor? since it IS a 1993 machine, its probably wasted electrolytics.
*ahem* I mean congratulations. You might also want to say hi over at 68kmla.net
Have you checked out the service manual?
There should be a convergence adjustment on the back of the video board, as well as the ones on top of the yoke.
If pot adjustments fail, you can try adjusting the yoke rings.
If you still need an analog board I have an extra - contact me by private message.
well the pots don't do anything. the pots on the top of the yoke work fine.
i broke the E/W ferrite screw in the side of the yoke to pieces trying to adjust it.
the back pot on the CRT neck board does NOTHING. i don't know if its the analog board, or the CRT.