mike944
New member
Hi everybody, i'm new here. I have a Baby Pacman with a WG4900 monitor. sorry for the long message, i'll try to describe it as best i can. I'll follow up with some pictures.
I just recapped it, and reassembled it. while trying to readjust everything, i noticed what appears to be a horizontal offset between the various colors. i don't remember whether it was there before the recap or not, but i think it was. Note: The monitor is 90deg to the normal orientation, but all my comments are referring to monitor directions, and ignore the fact that it's oriented sideways. When i say left, i mean monitor left. (the left-side is mounted towards the top)
I'm pretty sure the problem lies in the drive electronics, not the adjustments on the picture tube. I've moved just about every adjustment, and it doesn't seem to help or hurt anything.
I also messed with all the on-board horiz adjustments, and i can't seem to make it any better or worse.
Unfortunately, i don't have a signal generator, all i have is an oscilloscope, the color bar screen courtesy of the Bally video controller, and the horizontal line you can get by tying TP302 to ground. Unfortunately, since the problem is horizontal, the horizontal line doesn't help much. (is there a built-in vertical line?)
Using the color bars, and turning the screen control way down, i can get the problem to clearly appear as vertical colored lines on the right-hand side when there are vertical transitions between the black background and each color.
I went through the white balance adjustment on P7 of the WG 4900 manual, and i noticed that the line in step 5.6 sort-of "fades in" on the left side, and the right side has a "hot spot". Same thing when i remove the jumper and view the grey raster. the left side "fades-in" and the right side has a bold line.
Any ideas?
Thanks,
Mike
I just recapped it, and reassembled it. while trying to readjust everything, i noticed what appears to be a horizontal offset between the various colors. i don't remember whether it was there before the recap or not, but i think it was. Note: The monitor is 90deg to the normal orientation, but all my comments are referring to monitor directions, and ignore the fact that it's oriented sideways. When i say left, i mean monitor left. (the left-side is mounted towards the top)
I'm pretty sure the problem lies in the drive electronics, not the adjustments on the picture tube. I've moved just about every adjustment, and it doesn't seem to help or hurt anything.
I also messed with all the on-board horiz adjustments, and i can't seem to make it any better or worse.
Unfortunately, i don't have a signal generator, all i have is an oscilloscope, the color bar screen courtesy of the Bally video controller, and the horizontal line you can get by tying TP302 to ground. Unfortunately, since the problem is horizontal, the horizontal line doesn't help much. (is there a built-in vertical line?)
Using the color bars, and turning the screen control way down, i can get the problem to clearly appear as vertical colored lines on the right-hand side when there are vertical transitions between the black background and each color.
I went through the white balance adjustment on P7 of the WG 4900 manual, and i noticed that the line in step 5.6 sort-of "fades in" on the left side, and the right side has a "hot spot". Same thing when i remove the jumper and view the grey raster. the left side "fades-in" and the right side has a bold line.
Any ideas?
Thanks,
Mike
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