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KOF graphic issues

wevbster

wevbster

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Hello all

I have an original MVS KOF 98 with some graphic issues. I have a lot of games and this is the only one with issues - does anyone have any ideas what the issue could be?
Some pics of the issue:
IMG_20230315_011705.jpg
IMG_20230315_011823.jpg


If you need more pics, please let me know.
Thanks.
 
When i see that NeoGeo logo i always think a bad C1 ..... but something really bad here ... the first thing I do in these cases is clean both side of contacts with the fiberglass pen.
Obviously only this cart has this problem and you have tried other games on the same mvs board correct ?
After a good clean of contact you can desolder the C-Roms to read them and check the crc with the database to verify the integrity.
(Unfortunately these are all 8MB croms so you need a suitable eprom reader.)
If you dont get Z80 error or unibios crash the P-Rom is fine.
What about the audio ?
 
All the other games work on the same board - i also tried this game on a different board and the problem is the same.
I already clean the contacts but i can do a deeper clean. The audio is also bad. I was trying to avoid the C Roms desoldering until i ruled out all possibilities but maybe i'll have to do it.

Here some pics of the board:
IMG_20230316_175020.jpg
IMG_20230316_175043.jpg
 
To me it looks like an address line issue thats effecting both C and S roms. I would check continuity from P0-P23 at the cart edge to the NEO-273. If those look good try reflowing the NEO-273.
 
If the problem is on video and audio suggests that the problem is not in the c or v roms.
ProgSf1 ;( I have no experience with this model sorry.
 
C roms are sprites and S rom is fixed layer (text), both are on the CHA board.

If you look at his first picture both sprites and fix layer are having issues. They are both displaying valid looking data (ie the text is valid characters, its just the wrong ones). So this is likely pointing to an address line issue over a data line issue. Since the C and S roms share the same address lines on the cart edge it would make sense they would both be effected with an address line issue. The address lines on the cart edge go to the NEO-273, which is then responsible for passing them onto the correct roms based on a clock signal.

https://wiki.neogeodev.org/index.php?title=MVS_cartridge_pinout
https://wiki.neogeodev.org/index.php?title=NEO-273
 
Thank you all for your help.
I'll test the address lines from the cart edge and the NEO-273 and I let you know.
 
I tested the addresses between the cart edge and NEO-273 and I checked the other lines in/out from the NEO-273 and everything seems fine. I did a reflow but didn't work.
I have a CHA-256 free board - is it possible to move everything from the CHA-512 to the CHA-256 just to rule out the possibility of a bad NEO-273?
 
wevbster said:
I tested the addresses between the cart edge and NEO-273 and I checked the other lines in/out from the NEO-273 and everything seems fine. I did a reflow but didn't work.
I have a CHA-256 free board - is it possible to move everything from the CHA-512 to the CHA-256 just to rule out the possibility of a bad NEO-273?
Click to expand...
Not in this case:
CHA256 -> Up to 8 * 32Mbit ROMs (27C322) can be used for a maximum of 256Mbit.
Kof 98 are 8x 64Mbit CROM you need a full CHA 512 (64 * 8 = 512)

Senza titolo.png
 
I will probably do that - move all to a ProgBK1. I let you know if it works.
Thank you for your help.
 
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