Neo Geo guys, Can you help resurrect this cab??

sohchx

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This is my first Neo cab, granted it isn't dedicated 1 slot but it was cheap so I could'nt say no. Anyway,I have power to the switcher,the red LED on the PCB,the marquee, and I can hear the transformer running but I have no neck glow from the monitor and no sound. Should I be able to hear the transformer humming? There are a few wires coming from the PCB harness that are not hooked up, two reds and one brown. I do not know where they should be or if they are even used in this application. I also found a harness with wiring wrapped up inside the cab and do not know what thats for, pics of it are below. I have taken video of the wiring starting from the AC filter so that you guys can verify that the cab is wired correctly. I also took video of the crackling sound coming from the switcher, along with that you can hear the transformer hum in the background. Now,another issue is that the switcher and transformer come on just by plugging the game in. It will not shut off or on by using the main on/off switch, or the 3 way switch on the inside of the cab. To power it down it must be unplugged. Also the persons before me modified the Jamma harness pin out diagram in the manual but I have not checked if they wired the harness differently from what the manual says it should be.
 

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more pics, the end of the random wiring,the unhooked wires , and modified instructions.
 

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Do you have another JAMMA cabinet to try the board out in?

If so I would start there, no point in messing with the harness if the board doesn't work.

It is a nice cabinet, but wat is with the crazy player two controls?!?! I swear operators are so lazy, If I saw that cabinet in the arcade I wouldn't want to play as player 2!

It looks like the buttons are spaced wierd too, but it might just because there is no black around the buttons.

If you get it working, I would suggest you fix the layout on the CP.

new_buttons_3.jpg
 
If so I would start there, no point in messing with the harness if the board doesn't work.

It is a nice cabinet, but wat is with the crazy player two controls?!?! I swear operators are so lazy, If I saw that cabinet in the arcade I wouldn't want to play as player 2!

It looks like the buttons are spaced wierd too, but it might just because there is no black around the buttons.

If you get it working, I would suggest you fix the layout on the CP.

new_buttons_3.jpg

Wow !! your right I just noticed that. player 2's stick should be on the left. Geez something else I gotta fix now. I am not concerned with the board right now as that is not my main issue. I want to know why the monitor has no power. I have a few other working jamma cabs but how would I run the 1 slot in those? Are they plug and play?
 
Kinda hard to tell by the pics, BUT to answer your questions...

Opinion - Looks like its wired half decently! I'm kinda impressed! I do agree with the control panel though, that part sucks.

Unhooked wires from pcb - they're in the center of the plug I so I'm gonna guess that they're the test and service switch wires. Not necessary for it to work properly I don't think.

Black and white wiring coming from the PCB with the plug on it looks like it should go to the speaker, which may be the plug hanging down on the right in that one pic.

No neck glow on monitor= check the fuse on the monitor chassis. Get us a pic of the back of the monitor or find out what model it is. Kinda looks like a K7000 from the front.

Lastly, that extra wire harness may have been leftover from the jamma harness for stereo wiring on the Neo Geo board. Not sure if the single slot does stereo or not, but just hang onto it incase you do ever need it, for now you don't.

Hope that helps!


Edit: WHAT THE F---- KIND OF SCREW IS ON THAT MONITOR CHASSIS?!?!?!
 
Kinda hard to tell by the pics, BUT to answer your questions...

Opinion - Looks like its wired half decently! I'm kinda impressed! I do agree with the control panel though, that part sucks.

Unhooked wires from pcb - they're in the center of the plug I so I'm gonna guess that they're the test and service switch wires. Not necessary for it to work properly I don't think.

Black and white wiring coming from the PCB with the plug on it looks like it should go to the speaker, which may be the plug hanging down on the right in that one pic.

No neck glow on monitor= check the fuse on the monitor chassis. Get us a pic of the back of the monitor or find out what model it is. Kinda looks like a K7000 from the front.

Lastly, that extra wire harness may have been leftover from the jamma harness for stereo wiring on the Neo Geo board. Not sure if the single slot does stereo or not, but just hang onto it incase you do ever need it, for now you don't.

Hope that helps!


Edit: WHAT THE F---- KIND OF SCREW IS ON THAT MONITOR CHASSIS?!?!?!

That wiring loom in one of the pics is for stereo sound. Also, take a picture of the back of the monitor.

Fuse looks good on the chassis, chassis is a wells gardner 19k7602. I just noticed those long ass screws, guess they could'nt find short ones. I'll be changing those out.
 

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I didn't see anywhere that said you tested the switcher power supply. Check your voltages coming out of the switcher. If you get good reading there, then check to see if the monitor is getting power on the other side of the isolation transformer.
 
Yeah put your meter on AC and see if you have juice at the monitor power plug. If so, then you'll have to troubleshoot the chassis. If the fuse is good on the chassis thats a good sign its probably something stupid like a cold solder point. I'd start at that big white resistor thats standing up on the right side (if you're looking at it from the back).

As far as seeing if its playing blind, you'll have to connect a speaker up somehow.

I'd also do what the other person said and check your voltages on the switcher, make sure you're not toasting the board!
 
The green light is on, on the power supply, and that's not 'oh hell that never goes bad' lets trust it........ but it is 'oh hell that rarely goes bad' let's trust it.

I think his problem is that the speakers are unplugged, and the monitor is dead.

Question for ya; you sure that the power supply is what's making that noise, and not the monitor? The neckboard looks twisted all to hell on that monitor, wouldn't surprise me if somebody had hit it, and cracked the neck open on the tube. It'll make a hiss noise if you plug it in like that, kind of scary sounding.

The black and white wires coming off the pcb are the speaker connections, they've hacked another connector on, and if you look up and above the pcb to the left, you'll see the other side of the connector. Plug that in and your sound will work.

If the neck of the tube isn't cracked, you'll need to have your monitor board rebuilt.
 
The neckboard looks twisted all to hell on that monitor, wouldn't surprise me if somebody had hit it, and cracked the neck open on the tube.
Same thing I was thinking. Unplug the neckboard and see if it any pins are stuck in the neckboard. The neckboard shoulndn't be rotated like that.
 
I am at work and just did some testing on my interlock and main SPST switches. The interlock is good and the SPST is bad which would explain why the cab comes on when it's plugged in and cannot be shut off unless it is unplugged. I'll conduct more AC tests and reseating of the neck board when I get back home this afternoon. The AC test I conducted last night was tracked from the back of the filter to the transformer all the way up to the monitor plug all which gave me 120V. I then went from the monitor plug to the main switch and got 0V. Can I take my one slot unit out and plug it into another Jamma cab? Will it play if I do this?
 
Your 1 slot will plug into another JAMMA cab without modifying the cab's harness. The 1 slots are true JAMMA, not like the multi-slots which are "almost" JAMMA.
 
The green light is on, on the power supply, and that's not 'oh hell that never goes bad' lets trust it........ but it is 'oh hell that rarely goes bad' let's trust it.

I think his problem is that the speakers are unplugged, and the monitor is dead.

Question for ya; you sure that the power supply is what's making that noise, and not the monitor? The neckboard looks twisted all to hell on that monitor, wouldn't surprise me if somebody had hit it, and cracked the neck open on the tube. It'll make a hiss noise if you plug it in like that, kind of scary sounding.

The black and white wires coming off the pcb are the speaker connections, they've hacked another connector on, and if you look up and above the pcb to the left, you'll see the other side of the connector. Plug that in and your sound will work.

If the neck of the tube isn't cracked, you'll need to have your monitor board rebuilt.

The switcher is definately where that sound is coming from . I put my ear directly on it while it was running so there is no doubt.
 
Your 1 slot will plug into another JAMMA cab without modifying the cab's harness. The 1 slots are true JAMMA, not like the multi-slots which are "almost" JAMMA.

Ahhh ok good to know just wanted to check before I did so. I am highly curious about wether the 1 slot actually plays, I am seeing the red led when it is powered on. I'll plug it into another cab tonight.
 
In working on these, the best way to fix them quickly and inexpensively is to use deductive logic. It took me forever to figure some of this out, lol but I'm getting better and better at repairing them.


Your one slot almost suredly works. If it doesn't work, then you've somehow got a cabinet that has a bad monitor, plus no sound, plus a bad gameboard. Logically, that's almost impossible.

It's like testing resistors, resistors almost never short out, they always open. So when you test resistors, you look to see if any of them have too high of a value. If you test them in circuit and the value is too low, it's probably fine because logically resistors don't go bad that way. Etc.

To test your 1 slot, just plug the sound back in. If the sound works, then the board likely works. Sure it could have graphic issues, but the chances are the big problem with your game (and the reason it was sold) is the monitor doesn't work.

Good luck, let us know what happens.
 
BTW, the last pic in your second post and the first pic in your third post, are of the stereo speaker connector. This connector is used on MV-1 and MV-1f motherboards to output stereo sound to the speakers. It would connect to the side of the motherboard and the normal speaker + & - wires would be removed from the JAMMA connector. Your motherboard doesn't support it, it is a MV-1FZ. You should find the other end of the harness though, cause if it's hooked up to the speakers, you obviously won't have any sound.
 
Also, I just watched your first video and I'm pretty sure that the 2 wire connector in the last pic of your first post is for mono speaker connection. You will need to verify that the two wires are in the number "10" and "L" positions in the jamma connector. Your mother board has the "10" labled on it just below the jamma connector, and the "L" is directly behind it (see pic). If these two wires are in those slots on the jamma connector, wire them up to the speakers or at least one speaker and see if you have sound.
 

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