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Author Topic: Mixed up grounds - Galaxian Midway  (Read 1254 times)
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lesoleil70
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« on: December 27, 2014, 11:55:04 am »

http://www.arcade-museum.com/pinouts-game/7885.html

Hi - I've got a galxaian clone board that follows the pinouts of the midway in the above link.

I'm getting a lot of interference on the screen.

On one monitor RGB are ok, on another monitor they are also OK however the screen is scrolling, but both bleed white badly.

I've followed the pinouts and it would appear the ground that is being run to the monitor is pin 21, and not video ground from "S", which seems odd to me

Question is - is ground = ground and I should not care, or is this a clear case of a hack job and I should ensure video GND goes to the monitor, and the other GND be removed from the equation when running R,G,B,Sync and "Gnd" to the monitor.

Has anyone ever seen this before - common hack ?

If so, would a ground from elsewhere be the cause of these screen issues I'm having?



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"We don't give the fuck, what the fuck you think of this shit, alright!" - Jacobsen, J. "Arcade Outsiders Ep. 56" http://media.libsyn.com/media/vgo/arcade_out_ep_56.mp3 (12/02/14)
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