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Having trouble with an unknown board. Anyone recognize it?

P

Polish-Jack

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I am helping a friend fix a monitor for a Sega racing game I can't remember the name of right now. The screen was dead but I managed to get it working. I found some broken traces and a defective HOT. I have the CRT powering on now but I think I have a blanking issue. I get scrolling raster lines as if there was a vertical hold issue, but the vertical hold adjustment does not have any effect at all.

Can anyone identify this board so I can look for a Service Manual?
Anyone have any advice?

20240123_131826.jpg


20240123_132426.jpg
 
This board is kicking my butt. I fixed a couple K7000 boards and a K7200 but I am at a loss on how to proceed with this one. I've connected a CM TPG to it, and revived an old Sencore from the 90s. Both are showing the same problem: a de-synced picture with retrace lines showing no matter how the flyback is adjusted. I think its a blanking issue because the "retrace lines" are not angled. They are flat.
 
Nanaos don't have that handy dandy K7000 flowchart that makes things easy to troubleshoot. They are definetly much more complex chassis I would say. That's about all the help I can provide! When I run into a problem with NANAOS I don't even fuss with it, it goes straight to PNL video in Covina, California and they fix it right up.
 
I got to add, these chassis run 15khz and 24khz, are you sure you have it set to the correct resolution?
 
I figured it out! It was just a sync issue. I had a minor epiphany and turned off composite sync and provided the chassis independent -H and -V sync signals. It cleared everything up.

Thanks for helping, everyone!
 
This is an ms8 26SU , the issue you have is due to a 4.7kohm resistor just near the flyback and you will find into the flyback metal cage. Just locate and replace this resistor.
 
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