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Vectrex Video Faults


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#1 ToyguyVT OFFLINE  

ToyguyVT

    Space Invader

  • 15 posts
  • Location:Vermont USA

Posted Tue Jan 31, 2017 11:18 PM

Thanks to my new VecMulti I was able to finally run the test cartridge on my Vectrex and I can see it's got some video issues.  There's a tiny bit of misalignment in the Integrator test but the big issue is the linearity screen.  The top, bottom and left bright white bars look pretty good but the white bar on the right is completely missing and there seems to be a bit of bending or fold-over on the right edge but it may just be that the beam is driven too far past the edge.  

 

I know there are X and Y size controls on the power board, so that should be straightforward.  I suspect those adjustments will require a centering change though, so it looks like I'll be needing to use the magnets.  If I remember correctly from my old TV repair days, there's no need to loosen the yoke clamp screw, right?  The magnets will just rotate on their own?  The vertical/horizontal alignment of the image is fine so I should not need to mess with the yoke position.

 

On the Distortion 2 test, the pattern is nice and sharp and the lines evenly spaced, but there are small gaps in the lines in various places.  Any idea what causes that?  Distortion test 1 is hard to evaluate with the screen driven off the right edge for now but generally the triangles look OK.

 

I'm going to go ahead and order a full cap kit for the machine along with new integrator caps.  I have a scope so I can do the DAC adjustment for zero volts.

 

The rest of the tests seem mostly OK.  Sounds and controllers test well.  Deflection protect and brightness control also appear to work properly and focus is good in all locations.  






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