Fix KoF 98 carts

aha2940

aha2940

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Hi

I got 3 MVS KoF 98 carts. 2 of them have the same problem: crosshatch on my CMVS, white screen on my AES+converter, and one of them shows some colored dots and stuff, but nothing that even resembles a sprite. I tested the 3 CHAR boards, they all are perfect, so the issue is on the PROG boards. The problem is, they all are that PROGSF1 board, which uses the surface mounted P1 chip and the Altera IC to decrypt it. Is there any chance of fixing these carts or the only chance it transplanting the chips to a BK1 board? any way to better diagnose the problem?

Thanks!!

Edit: I already tried cleaning the carts with everything I know, Alcohol, de-oxit, nothing works.
 
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RabbitTroop

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Just wondering, because I know James or one of the techs with real component knowledge will probably stumble into this thread and help you... but for all the board tech out there... Have you guys tried to replace this chip? They're pretty cheap on eBay. I know there are ways to remove it completely, but is that chip's decryption unique per game (probably not) or just like an XOR or something (probably). ;) Might be able to just swap these out as they die.
 
aha2940

aha2940

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RabbitTroop said:
Just wondering, because I know James or one of the techs with real component knowledge will probably stumble into this thread and help you... but for all the board tech out there... Have you guys tried to replace this chip? They're pretty cheap on eBay. I know there are ways to remove it completely, but is that chip's decryption unique per game (probably not) or just like an XOR or something (probably). ;) Might be able to just swap these out as they die.
Click to expand...

AFAIK, the biggest issue replacing them is the programming. These chips are processors and you can upload a program to them.

Regards.
 
shadowkn55

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There are official roms available for kof98 that use the standard bk1.
 
shadowkn55

shadowkn55

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aha2940 said:
Thanks for the help guys. So, from your replies, should I infer that these PROGSF1 boards are not repairable? :(

Thanks!
Click to expand...

It's probably not worth your time. The problem with the altera chip burning will happen again eventually.
 
aha2940

aha2940

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shadowkn55 said:
It's probably not worth your time. The problem with the altera chip burning will happen again eventually.
Click to expand...

Thanks shadowkn55. Now other two questions:

1. Where can I get BK1 boards without saccing a cart?
2. After this change, the carts would be considered boots, I guess? so that means I get stuck with them because the forums do not allow selling boots?

Thanks!!
 
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Pedrobear

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Looking at the protection (4 bytes rom overlay), it should de fairly simple to rewrite it.

Do you have an unibios to check memory from cross hatch screen ?
 
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aha2940

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Pedrobear said:
Do you have an unibios to check memory from cross hatch screen ?
Click to expand...

Yes, my CMVS has UniBIOS. When it boots to crosshatch, it gives me two options. IIRC, button B is Mem Viewer, but when I press it it shows a black screen. Am I doing something wrong?

Thanks!!
 
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Pedrobear

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It's D to mem viewer, should gives you a screen like this:
0002.png

Not sure what would cause a black screen, fried carts can do unexpected things.

Was just wondering if some data was passing through altera chip or nothing at all.
 
Atro

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I have a fried one at home, but I cannot be of any help coz I don't have any Unibios-capable board there.
I'm also curious if a cart who's fried at 10V could be repaired at all.
 
GadgetUK

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I would have thought it possible to replace encrypted P ROMs with decrypted versions, but some board mods would be required. Not sure if additional logic might need adding as well. What causes the fault on these boards btw?
 
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Pedrobear

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Seems the Altera CPLD goes faulty, either it's less temper resistant than the average MVS board or data gets corrupted over time, as it's a programmable device.

I guess you can hook a JTAG cable, see if the chip is plain dead or just corrupted. And no you can't read the chip (read protected) :(
 
bustedstr8

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GadgetUK said:
I would have thought it possible to replace encrypted P ROMs with decrypted versions, but some board mods would be required. Not sure if additional logic might need adding as well. What causes the fault on these boards btw?
Click to expand...

I'm thinking you could....but it would be a rat nest of jumper wires and glue logic everywhere :p Sacking a $15 KOF95 for the BK1 sounds like a cooler party by far.
 
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aha2940

aha2940

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Pedrobear said:
It's D to mem viewer, should gives you a screen like this:
View attachment 20059

Not sure what would cause a black screen, fried carts can do unexpected things.

Was just wondering if some data was passing through altera chip or nothing at all.
Click to expand...

Thanks for your help, it seems I was doing something wrong as this time 2 of 3 boards let me use the Memory Viewer. It shows nothing at all, no values changing and the first values of the viewer look exactly the same as your screenshot. The 3rd board shows either a solid screen of colors (got white, blue or Magenta) or some colors moving horizontally, like an encrypted TV channel in the 90's (Hello Cinemax)

Pedrobear said:
Seems the Altera CPLD goes faulty, either it's less temper resistant than the average MVS board or data gets corrupted over time, as it's a programmable device.

I guess you can hook a JTAG cable, see if the chip is plain dead or just corrupted. And no you can't read the chip (read protected) :(
Click to expand...

The JTAG option seems intriguing. The board has a 10-pin CON1 connector, it seems to be the JTAG connector. Any ideas on how to access it?

Thanks!!
 
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Pedrobear

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The chip does address decoding, you shouldn't get correct values if it's dead. Can you scroll around and screenshot 0x000, 0x100 and 0x800 addresses data?

You need to solder the 10 pin header and use an USB blaster to get the JTAG going. Must install Quartus too I guess.
 
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