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Missing Logo/weird "Shadows" on sprites for Bad Dudes

Nearlylogical

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Greetings. I'm a new to this hobby. I impulse bought a Bad Dudes vs Dragon Ninja at a garage sale. It was marked as working. I then needed some way to play it so I ordered a Parsec Supergun PCB and the parts and I assembled it. Finally the Parsec uses an ATX power supply so I pulled a 550w Corsair PSU out of an old Computer That I still had laying around. When I turned on the game it was mostly working, but the logo/characters/text doesn't appear and in the game all the sprites have this weird shadow (see attached image). I checked the voltages on the 5v(4.96) and 12v(12.01) lines and they are in spec for the board.

Basically I can't say any part of my setup is "Known Good" and I don't have any extra superguns or arcade boards to try. So I'm a loss as to what to look at next. Has anyone seen anything like this before? Any idea which component is the likely cause or even better information about where to start looking?

Thanks!
 

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Hey there!

Your voltages are ok, they shouldn't cause an issue.
There's something you can try that is easy to do and is something that may help.
You need to remove the chips that are socketed and put them back again. You can use a small flat screwdriver for this. Lift a little bit from one side and then from the other. Try to not bend the pins or scratch the board when doing this, you may cause more damage accidentally.
When putting them back push the chip gently back again. Make sure the pins are aligned and that they don't become bent. If they do, straighten them and repeat the process.

See if that helps. If not, post good pictures of the board and me or someone else will take a look for something out of the ordinary.
 
I resocketed all the rom chips but one large Intel chip which was effectively blocked by a large capacitor. I can make a try at it later but while I had it apart I took some pictures of the board. Additionally I'll link to a video of the game in action. The lack of sound is an issue with my camera not the game. I am wondering if this could be caused by me not having a controller connected, but I can see how. The board looks to be in very good condition which is why I impulse bought it in the first place. :\

Photos:
https://www.dropbox.com/s/uzkj4q9oonqiw4f/IMG_20200904_181758.jpg?dl=0
https://www.dropbox.com/s/wr9fx5xewho7m68/IMG_20200904_181822.jpg?dl=0
https://www.dropbox.com/s/zzmus23sl4sb7g0/IMG_20200904_181839.jpg?dl=0
https://www.dropbox.com/s/7fioc6ocv2x4ibp/IMG_20200904_181905.jpg?dl=0

Video:
https://www.dropbox.com/s/5nucn6c4x81g93t/VID_20200904_182805.mp4?dl=0
 
Hello again!

The board looks to be in fantastic shape with no obvious damage or any oxidation that could be causing this issue.

The fact you didn't connect any controller is not related to the fault. From the board's point of view you're just not pressing any button. No problems there.

Unfortunately, you'll have to get someone to send the board to and actually diagnose the fault and repair it.

I was hoping the issue was caused by a bad contact in one of the sockets in one of the graphics ROMs. It happens even though it felt unlikely.

At this point I'm leaning towards a failed IC or RAM in the graphics section. Finding the fault requires a fair bit of probing and replacing these chips should not be done by a beginner.

Look around the forum for a tech from the US.

A final word: this stuff happens. Don't be discouraged by this experience. It's like owning an old car, you have to accept parts will fail and they'll have to be fixed.

Best of luck!
 
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