Mortal Kombat I Restoration/MAME!

[JasonSmith]

I just bought an original Mortal Kombat cabinet.  I'm planning on restoring it and also making it into a MAME cabinet.  This is my first stab at doing anything arcade machine related, however I am very fluent with the innards and workings of PC's.  I was told the game worked "as far as they knew", but the power cable was cut.  I spliced a new end on machine's power cable and plugged it in.  I turned the power on and nothing seemed to happen.  However, when I powered the machine off the monitor "powered off".  It drew the little rectangular box for a second you'd expect a CRT to draw when shut down.  So I know it's at least getting power.  Note that not even the marquee lights up.  The bulb may be bad, though, I have no idea.

I decided to open it up to see if I could see what was going on inside.  I found three connectors that were loose. Two of them obviously went together, same number of pins, colors matched on both ends, etc.  I have one left over connector that I have no idea what it goes to.  I've tried following the cables and they go back to the game's pcb, but I'm having a hard time determining to what pins exactly.  I've tried looking online at an MK1 manual I found, but none of the colors seem to match anything that would be near that connector in the wiring scheme.

However, my biggest concern was what I think to be a ground cable that is just hanging out in the cab loose.  It looks like it should go near to the monitor or attach to the monitor chassis somewhere, but I have no idea.  I have the cab unplugged and will leave it so until I know what that is and where that goes.  I'm hoping a few of you can help me determine what that "ground" cable is and what the mystery connector is. 

I've attached some pictures of the mystery connector along with a picture of the ground cable.  On the underside of the monitor chassis there is a diagram for the monitor schematics as well.  I attached that too, if that will help anyone.

I've refrained from using a multimeter or doing much testing because that cable that I suspect to be a ground cable makes me nervous.  Any input is helpful.

Thanks very much!  I've been lurking the forum for a few weeks now trying to study up on what I am doing exactly.  This is a great resource and I'm glad this community exists!

[Spyridon]

I just bought an original Mortal Kombat cabinet.  I'm planning on restoring it and also making it into a MAME cabinet. 

Welcome to project annoucements section (and that would be converting...not restoring)  (but it's a jamma cab so who cares!)

I decided to open it up to see if I could see what was going on inside.  I found three connectors that were loose. Two of them obviously went together, same number of pins, colors matched on both ends, etc.  I have one left over connector that I have no idea what it goes to.  I've tried following the cables and they go back to the game's pcb, but I'm having a hard time determining to what pins exactly.  I've tried looking online at an MK1 manual I found, but none of the colors seem to match anything that would be near that connector in the wiring scheme.

That looks like it may be the connector that goes to the monitor.  Do you have anything going from the PCB to the monitor already?

However, my biggest concern was what I think to be a ground cable that is just hanging out in the cab loose.  It looks like it should go near to the monitor or attach to the monitor chassis somewhere, but I have no idea.  I have the cab unplugged and will leave it so until I know what that is and where that goes.  I'm hoping a few of you can help me determine what that "ground" cable is and what the mystery connector is. 

Yes, that is the ground wire.  Just find a screw on the metal chassis to connect it to.

[JasonSmith]

I'm unable to look at the cabinet at the moment, but I believe everything that goes to the monitor is shown in the picture with the ground wire.  I'm pretty sure there is more wiring that runs up, but I'm thinking they go to the speakers.

And for the grounding, just attach it to the chassis for the monitor?

And lastly, I'm going to keep all the original MK1 stuff in the cabinet.  I can't remember what it's called, but I found a device that will allow you to switch from MAME back to a jamma setup(I have a bookmark for it on my home machine).  So it's both a restoration and a conversion.  : )

Thanks for your help!  I learn best by taking things apart and getting my hands dirty, but starting with a broken cabinet kind of slows that process down.  I appreciate even suggestions to get me going.

Thanks!

[adidas1984x]

put some more pics of the cabinet up i love mk

[JasonSmith]

Certainly   I'll take some and post them later.  Not near the cabinet at the moment.

The artwork is pretty faded on the sides, however

I have a lot of restoring to the cabinet to do.

[Spyridon]

Certainly   I'll take some and post them later. 

Take some pics of the outside so we can see what you are dealing with from a cosmetic point, but also more pics of the inside.  Step back a bit and give a bigger picture of the monitor.  Also would like to see more of the wireing including where your mysterious wire is connected on the board.

[JasonSmith]

Well, I put a little more effort with a better light source into following the mystery connector and it plugs into J4 on the Jamma board, which connects to buttons on the control panel according to the manual I have.  I likely have some buttons that need to be hooked up. 

I'll reattach that ground cable, figure out what on the control panel that connector hooks into, then give it another shot.  And just to clarify, I can hook that ground cable to the metal chassis of the monitor?

My cellphone doesn't handle poor lighting very well, so most of my shots of the outside of the cabinet didn't turn out very well.  I'll take more tonight.

I numbered the pics.

1.  Just a shot of the control panel.

2.  A wider shot of the inside of the cabinet (pretty dusty yet).

3.  Another wider shot looking up towards the monitor.

4.  A closer look at the board where my mystery connector follows back into the board.  The bottom right connector(J4) is where those wires lead.  As I said, according to the manual those are for the player controls.  The manual tells which buttons they are supposed to be, so it should be easy to follow those and figure out what the heck is going on.

I have a feeling this won't give me much affect with regards to the machine powering on and working properly(unless the ground being unplugged can cause that?), but it needs to be figured out regardless.  Right now I'm suspecting it's a power supply issue with my previous knowledge of the innards of a PC.

Thanks for your help guys.  Any other tips/help or potential warnings of pitfalls are appreciated.  I'll keep updating as I go!

EDIT:  I'll just ask this now to hopefully get some advice or an answer sooner.  If I still can't get it to power up, what should be my next steps?  What do I have to do to get a new power supply or replace it with a standard PC power supply or something?  The monitor has an isolation transformer(can be seen at the center of the bottom of the cabinet) if that makes any difference.  Thanks again!

[JasonSmith]

Well, I checked into the buttons and they are all wired and appear to go into the big jamma connector.  The book I have might be different than what I have.

Two of the wires do go into the J4 connector, 1 of them goes to the +12v on the power supply, and the other is a black wire which I'm assuming is a ground or negative.  It's a little harder to follow.

I'm not sure what this means.  I assume this is something related to the coin door, but that appears to be all wired up too.  There is the empty box spot below the coin slots.  Should there be a powered unit down below?  Or is it just an empty metal area to collect coins?  Maybe that cable is supposed to go to something there.

Thanks

[RayB]

Ground wire to the monitor FRAME.

[JasonSmith]

Well, the beast is up and running!!

Everything seems to be working wonderfully after rewiring everything and replacing the power supply with one from suzo happ.  A few questions, though.  The audio seems really finicky.  The volume control is on a little breakout box inside the cabinet that is easily accessible from the front door on the cabinet.  However, whenever I turn the dial the audio jumps to full or to none at all.  And it'll usually adjust on it's own without me even touching it.  I'm probably going to take the volume control apart and clean it for starters and make sure there is nothing contacting that shouldn't be.  Anyone have an experience/tips for something like that?

Also, I'm going to be setting up mame in the cabinet now that the MK1 functions are restored.  I'm probably going with a j-pac and an arcade vga from ultimarc.  Anyone have any experience with an MK cab and this setup?  The MK cab has 5 buttons for each player as well as the start buttons.  The j-pac should handle that ok.  Any other "to be aware of's" that anyone can foresee?

Also, I just got a pocket hd recorder, so I'll post vids soon. 

[BobA]

Well, the beast is up and running!!

The audio seems really finicky.  The volume control is on a little breakout box inside the cabinet that is easily accessible from the front door on the cabinet.  However, whenever I turn the dial the audio jumps to full or to none at all.  And it'll usually adjust on it's own without me even touching it.  I'm probably going to take the volume control apart and clean it for starters and make sure there is nothing contacting that shouldn't be.  Anyone have an experience/tips for something like that?

I have used Nutrol before and it can restore a dirty pot if it is not totally worn out.
Cleaner Lubricant

A jpac should handle your controls ok.  You may have to check where the additional buttons are wired on the jamma harness since they are not on a kick harness and wire them to the extra terminals on the jpac.

[kalars123]

Well, the beast is up and running!!

Everything seems to be working wonderfully after rewiring everything and replacing the power supply with one from suzo happ.  A few questions, though.  The audio seems really finicky.  The volume control is on a little breakout box inside the cabinet that is easily accessible from the front door on the cabinet.  However, whenever I turn the dial the audio jumps to full or to none at all.  And it'll usually adjust on it's own without me even touching it.  I'm probably going to take the volume control apart and clean it for starters and make sure there is nothing contacting that shouldn't be.  Anyone have an experience/tips for something like that?

Also, I'm going to be setting up mame in the cabinet now that the MK1 functions are restored.  I'm probably going with a j-pac and an arcade vga from ultimarc.  Anyone have any experience with an MK cab and this setup?  The MK cab has 5 buttons for each player as well as the start buttons.  The j-pac should handle that ok.  Any other "to be aware of's" that anyone can foresee?

Also, I just got a pocket hd recorder, so I'll post vids soon. 

I have a MK cabinet also that I'm restoring/Mameing, for the audio i would check all your wires and make sure there are no ground outs as that will automatically make your sound go max, i also am using a Jpac/avga setup, it was VERY simple to get going with this cabinet though i have modified that control panel for 7 buttons aka SF layout with MK3 run button, the monitor is VERY finiky about what resolutions you send to it at what refresh i run my desktop and FE at 320x240 and it's a crystal clear picture, you will have to adjust your monitor settings for 640x480 though so that you get a mostly full screen picture for all the game resolution's, doing this may/may not cause over-scan to occur at the top/bottom of the screen if it does adjust the 50/60hz pot on the monitor main-board to get a clear picture it is VERY sensitive just a little will do it.

in short i'm doing the EXACT same thing as you so if you have any question's just holler.