Assault missing colors

manadams

Well-known member

Donor 2015
Joined
May 12, 2015
Messages
2,282
Reaction score
568
Location
Loveland, Colorado
Some colors are missing and replaced with grey, the text at the bottom of the main screen should be a light pink color and NAMCO should be red. Other pages have white instead of a black background. It's not the monitor and filter board has been removed. The only screen that shows up in self test is the color test pattern which I assume is because those colors are missing on those test screens.


 
The palette generation circuit uses same design of the Namco System 1 hardware.On video PCB there are three 6264 static RAM (one for each color), the bits from their data lines are fed into the custom C116 whose outputs are converted to analog from a resistor ladder.Lastly there is a transistor which amplify the signal and outputs it to JAMMA connector pin.
See page 71-72 of this PDF:

http://www.gallopingghostarcade.com/qr/assault/manual.pdf
 
I'm getting all the colors on the color test pattern in the self test, could this be a color inversion issue based on the top picture's white background should be black?
 
Back
Top Bottom