Whats wrong with this picture?

Vraz

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I was testing my Defender PCB with a K49XX in my JAMMA Robocop and got an unexpected result. The image is rotated 180 degrees. I have not had time to dig into it and was hoping someone had a simple explanation. Have not tried this monitor with any other boards besides Robocop (which is upside up). What the heck is going on?

upside.jpg
 
There is nothing wrong. Your monitor's yoke wiring is set up to work fine with Robocop, which is the game the monitor is in. The Defender PCB output the picture in a different way, so they image looks upside down. If you were going to leave Defender hooked up, then you'd need Dokert's link. If you're not, then just know that the board works and hook your Robocop back up....
 
Consider yourself lucky. I had to try to hook my Defender boards to at least 4 different games and all I got was a scrambled sync issue on all 4. I would have killed for an upside down image.

But Im not gonna lie, I gave a nice hearty chuckle when I saw that pic.
 
FWIW, if you... for whatever reason... want to be able to hook up Defender AND Robocop to that monitor... flip the yoke wires then on Robocop, on SW#1 flip switch 7 to the other setting (either off if it's on, or on if it's off)... that'll flip the screen for Robocop to make it match up to your monitor's new yoke wiring.

http://www.crazykong.com/dips/Robocop.txt
 
Thanks for the many replies! Using all this great information plus some follow up googling, it all makes sense now. I wanted to understand which of the games was actually producing the reversed image as I figure its best to have all monitors/yokes setup to scan from top-left to bottom-right (especially since the JAMMA cab is meant for testing). Defender has jumper W1 which lets it flip, but mine was present. Turns out Robocopy SW1-7 is set off which is documented as "reversed". So it would appear the K4900 yoke in that cabinet is reversed for some reason.

I will double check with another board to be certain, but assuming that is the case, will try to reverse the yoke on the K4900 (and then set Robocop to "normal"). Looks like there are individual molex connectors for horiz/vert so that is good. Placement is nasty as I have to stick my hand between the CRT and flyback to get at them. Will definitely be leaving the discharge clip in place for that little adventure.
 
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