Mortal Kombat repair log...

ifkz

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SYMPTOM: Game would not boot, black screen.

SOLUTION: I got this PCB a bit ago and I found it had a couple of problems that were pretty obvious. It was missing an EPROM at location U89. In the place of an EPROM was a socket extender that had ruined the socket. I also found a strange EPROM marked as a "Kombo Pack" The back of the board was scratched up, but a beep test confirmed all was okay.

A good place to start was to return this to a factory code base. I quickly found out it was rev.3 of the software and I found some blank EPROMS to program. I also fitted a replacement socket for the trashed U89. At boot, I was greeted by a working game!

I have no sound card, or the JAMMA+ harness, but it is somewhat playable.

The only unresolved issue I can see is some static around the first level crowd of monks. No biggie.
 
ever ran into anything dealing with RAMs on these? I assume you are referring entirely to the Y-unit versions.
 
I'm thinking the extender socket he's talking about might have been from one of the Hacks like Nifty Kombo/Ninja ect...

I'd pull all the chips one at a time and clean up the legs with some super fine grit sand paper (as instructed by Mecha many many times :D )
 
I don't know what version, but the static is only on this one stage, in the center of the screen, and isn't confined to the monks, characters, etc. It is very minor and an EPROM cleaning will take care of it, I'm sure.

How much does a replacement sound board run nowadays?

EDIT: Some pictures!

My board
HPIM1393.jpg


The slight static issue, pretty minor
HPIM1396.jpg
 
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take a pic of the expansion board you removed if you can, it seems to me that it was a hack upgrade. as you have a 8mb chip board and not the 4mb with the memory expansion board.

Hit the old chips with some fine grit (and check for spider webs/dust bunnies under those chips) (this is another one of mecha's teachings :D ).

The soundboard should be found in the $15-$30 range shipped. you'll need the cabling to it that bob roberts carries (which will probably run you another $30 with the kick harness)

Looks like you need a CMOS battery too :D
 
take a pic of the expansion board you removed if you can, it seems to me that it was a hack upgrade. as you have a 8mb chip board and not the 4mb with the memory expansion board.

Hit the old chips with some fine grit (and check for spider webs/dust bunnies under those chips) (this is another one of mecha's teachings :D ).

The soundboard should be found in the $15-$30 range shipped. you'll need the cabling to it that bob roberts carries (which will probably run you another $30 with the kick harness)

Looks like you need a CMOS battery too :D

I think you're confused with MK2. lol only MK2 had the expansion board or 8 mb rom option.

Y-units only had 4 meg roms, or maybe even smaller on older games I'm sure.
 
I think you're confused with MK2. lol only MK2 had the expansion board or 8 mb rom option.

Y-units only had 4 meg roms, or maybe even smaller on older games I'm sure.

thanks, it's late. :D
 
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