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Mortal Kombat 1 Sound Help

SEGASHIRO

SEGASHIRO

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Hi,

I was wondering if anyone knew where to get or could make replacement sounds wires for Mortal Kombat 1. I almost have my hands on a working pcb and sound board but it lacks the wires to hook the two together - can anyone help?

Cheers & Thanks you!
 
Hey,

So, I looked into it a bit more and it looks to be a Y-Unit with no ribbon cable and no power cable. I would need both.

The seller assumes that the sound board works as it is very clean and came with the working main board and was sold to him as working. He apparently used alligator clips/and a ribbon cable to connect the necessary power to the sound board. He did run test mode and knows that it came back testing ok (it might have just been testing the roms in test mode).

However he got no sound from the board but it seems that all the logic in the sound board works fine. But he doesn't know if the sound board has another issue.

What do you fine folks think, should I take the jump? Can I get the cables from someone here?
 
There are two pins that need to be connected for any sound to work. There is often a volume control pot connecting these two. Though you can connect the pins and have full blast sound that is controlled elsewhere in the cab. I don't have a pcb in front of me to tell you which header is for what.

Regardless all cables are fairly easy to make.
 
Just an update. I got my sound wires in. The game boots and plays but all I get is static through the speakers. The static gets louder as I move the volume pot. The game is seeming to play fine but just without sound.

The board is getting 5V at the Jamma Harness. When I go to the test menu, I get the following errors:

Error - Sound IRQ Not Detected


0 Tones – Check Hardware
1 Tone – Sound Board Ok
2 Tones- RAM error U2
3 Tones – ROM error U3

I doubled checked the wiring and the serial cable is connected correctly.

Is there anyway to fix this or is the sound board screwed up? Replacements seem very expensive on ebay. Anyone got the skills to make this work again? MK just isn't the same without the sound.
 
I measured the -5V on the suzo-happ power supply and it was coming off at -4.6. I will take photos and post them tonight. I am also using the HAS to test.

Also, on the board, a few the roms don't have UV stickers on them. Is there anything special I should use to cover them? Or are they fine being open?

I could try it in a cab as well.
 
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I've got a MK2 board, I've found that you need both a very strong -5v AND +12v for sound.
If you have a mild amount of static, turn the volume pot on the board way way down and turn your cab amp up.

If you have ROM errors try to re-seat chips first, then check the socket pins for continuity to the backside with a multi-meter.
The RAM error tho... I've found these Midway boards have allot of problems with dry joints, or pop'd solder joins.
If you can, re-flow the surface mounted chips with a steady pressure.

If none of the above helps (it wasn't enuf to save my board) I might know someone who can fix it for you (he fixed mine).
 
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Pictures! Taken from my cell phone. Let me know if anyone needs to see anything specific. It is a Y-unit board. I tried turning up the voltage. I didn't check the continuity yet but the RAM chip doesn't seem to wiggle. Again, I haven't tested in the cabinet yet.

Working Graphics:

workingscreen1.jpg


Sound Board Test:

testwiring.jpg

LED Lights on Main Board: (When the board powers up for me LED1 stays lit up but LED2 flashes ... I'm not sure if that is supposed to happen).

LED2.jpg

Wiring Connects: (I tried to align the red stripe with pin #1 and #2 on both the sound board and main board, the sound pot came with the board)

Soundboardwiring.jpg
ribboncable mainboard.jpg


Sound Board ROMS: (U2 and U3 are the two giving an error. I reseated U2. Nothing changed still no sound. Do the ROM/RAM chips need changing? Also I've heard that the crystal can give problems).

Soundboardroms.jpg

I can't wait to get the sound working!
 

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That doesn't look like the ribbon cable that came with it. Did you try connecting it so that the cable hangs off the edge of the pcb rather than into it? AKA line the red stripe to pin 26 on both?
 
From the pic you have one of the connectors on the ribbon cable reversed, flip one of those around and test again.
 
I will try that now...I flipped the wire so the red stripe was at the pin 26 on both. Static came back from the first time I tested before trying to align the red stripe to pin 1&2.

I tested again, same errors as previously U2/U3 and sound IRQ.
 
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I have read that those 2 chips could be replaced and/or reprogrammed, but most just replace the sound board all together. I will keep looking to see if there is a fix for it.
 
Hey, any luck on your end with the sound issue? Everything points towards replacing the sound board.
 
Not yet...I was going to buy a new 20 pin cable. According to the MKsource guy on youtube that would be the main culprit in the Sound IRQ error. So, I am going to try find another cable first before figuring out if I need to get a replacement board or send it off to get the ROM/RAM chips repaired.
 
I crimped to new cables and tested both. Still no sound and the same errors. I haven't checked continuity yet but that may be my mini-project for tomorrow.
 
Yeah, I still have this issue. Does anyone know someone who can fix an MK soundboard? There seems to be tons of broken ones on ebay but not a lot of working ones.
 
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