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Brentradio

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What's up!

I finally got my Sega 16 jamma adapter so I can finally test this Altered Beast pcb I purchased for $40 for the Sega 16b Multi game.

He said it did have a graphics glitch and it does.

So I am wondering if this may be an easy fix or will the multi fix it for me?

White lines through most/all moving characters.

DSCN3327.JPG


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Apocalypse

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Typical faulty ROM symptoms (stuck data line).
Could be as easy as burning a replacement ROM if you're lucky.
 

Brentradio

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Any specific ROM I should replace?

And would the multi kit fix it if that was the problem?

Thanks!

:D
 

Brentradio

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Upon further inspection, after reseating each ROM, I came across one with a bent pin that was not in the socket.

You can see the Red Arrows pointing to the chip and the bent pin in this photo from the original auction I bought the board from.

I tried to straighten it out, but no effect.

Would you know what ROM this is?

The ROM to the right says:
MPR 11679
Sharp Japan
8829 D

The ROM with the Red Arrows (and bent pin) says:
MPR 11678
Sharp Japan
8829 D

The ROM to the left says:
MPR 11677
Sharp Japan
8829 D

If this is the problem, I'm assuming I would need a Sharp Japan 8829 D chip with the MPR 11678 rom image?

But I really have no idea.

Thanks!

DSCN3176pin.JPG
 

ekorz

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The B row are the sprite roms. You can reburn them using normal 27c1001 / 27c010 or 271000 jedec like is being used on b4 and b8 in your photo. You could double the file and put it on a 27c020.

I assume you can find the rom files online. Pretty sure any revision will have the same sprite rom data.
 

Brentradio

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So I replaced the chip with the arrow, (the bent pin chip) with a newly burned one, but the problem is still the same.

My main question would be, if there is a bad rom on my board, will the multi-kit take care of it?
 

Brentradio

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While messing around with this board today, I noticed that there is an open socket (bottom left corner in pic above)

Is this socket meant to be empty? If not, what chip would go there?

Hopefully this is what the problem is.

Thanks!
 
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