MKII sound not working, what are the odds?

it looks like the battery's dead. so in either case, the default volume should still kick in, and be loud enough to hear the BONG! sound on power up.

I was just wondering if the dedicated MK cab had the speaker wiring done differently or something, but I would think it wouldn't make a difference, the speaker output should come out of the JAMMA harness no matter what.

I just thought I read one time that the volume pot like interrupts between the JAMMA edge and the speakers in dedicated MK... but what about the volume pot connector on the sound board? that's the part that doesn't make sense.
 
I'm no scholar on this subject, but considering that the sound board is in fact turning up as working in the test mode, what's the likelihood that the amp chip is just bad on the sound board? that shouldn't interfere with any of the sound boards internal operations, just driving the amplifier.

there's a couple of empty terminals on the sound board, I think they say "AUX OUT", and don't quote me, but I think those go around the amplification, theoretically, you could probably hook up an RCA jack you can get at Radio Shack and try plugging that into a TV or something and see if you get sound that way.

I figure it's just a couple wires. I bought a bunch of RCA jacks for that exact purpose, thinking I'd be doing a video project with a Supergun and be able to capture video and audio that way, but I seriously lost them, otherwise I'd try this myself.
 
I have several mk 1 and II boards when i link them in my cab i have to change the speaker wires also. mk2 dosent like the volume pot verry well its not required at all i would put a switch in for the speaker wires. try and take wires directally from the jamma harness to the speakers you'll have to cut them temporally but that could let you know your boards arn't bad
 
you think it interferes or something?

welove80s, just try unplugging the volume pot. lol

this is something I never tried before, never ran my MK1 and MK2 in the same cab like that.
 
I run mk 1, 2, 3, 4 all in the same cab and i have to switch the pot/speaker wires whenever i run 2, 3, 4 or i have no sound its a little work i usually play mk II its my favorite then 1 and 3. 4 is just to complete the quadtrigally it isnt verry fun but its a mk4 cab so why not. also when you run the secondary inputs togather it messes with the games put them on a selector
 
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yeah, I know all about that routine. lol what's sidelined my "Multi Kombat" project is the fact that I went to all the trouble of soldering the diodes inline with all the kick buttons BACKWARDS. whoops. :)

what doesn't make sense is you can run MK1 in a switcher with the other games just fine. why is that, because the JAMMA speaker wiring is controlled and shut off by relay?
 
I don't see what the volume pot would have to do with the Jamma harness. The speakers are connected through the Jamma harness and the volume pot only controls the volume of the sound coming from the PCB going into the Jamma harness. In other words the volume pot isn't wired into the Jamma harness directly in any way so there shouldn't be any interference from it.

Like Mitsurugi-w said, flip the ribbon cable and see what that does. If not there could be an issue with the amp like Mecha187 suggested. Especially if the board test doesn't say there is anything wrong with the roms or board.

I haven't fired up my MK2 board in a while but might have to pull it out and test in my MK cab to see if mine works ok.

I just checked out the pinouts for both boards and the only difference is pins K and 9. On the Mortal Kombat board these are for "coin lockout". MK2 doesn't use these and it shouldn't make a difference but you might want to see if they're on your harness and disable them just to make sure it in fact doesn't make a difference.
 
Have you gone into the menu screen and tried adjusting the volume there?
Ummm yep, late in the video I tried that.

it looks like the battery's dead. so in either case, the default volume should still kick in, and be loud enough to hear the BONG! sound on power up.

I was just wondering if the dedicated MK cab had the speaker wiring done differently or something, but I would think it wouldn't make a difference, the speaker output should come out of the JAMMA harness no matter what.

I just thought I read one time that the volume pot like interrupts between the JAMMA edge and the speakers in dedicated MK... but what about the volume pot connector on the sound board? that's the part that doesn't make sense.
Yes, I found out I have a dead battery. I have a replacement, just havent installed it yet. But you are right, that shouldnt affect the sound, as far as I can tell it only save your coin and game options, high scores, winning streaks ect.

The volume pot has 2 wires and goes directly into a connector on the main MK PCB. Speaker wires are going directly to the JAMMA Harness. I can try unplugging it, but like I mentioned, shouldnt have anything to do with it.

Turn the ribbon cable connector on the sound board around so that the cable leads away from the board rather than into it.
But only switch the connector on the sound board. The main pcb looked fine. That's how mine is in my cab.
I can try swapping both ends, but as far as I can tell it wont make a difference. If I only swap one end, It wont be connected right. Theres a red stripe on the ribbon cable, indicating that goes to pin 1 on each PCB. Unless someone can confirm otherwise, I dont want to chance any more damage.
I don't see what the volume pot would have to do with the Jamma harness. The speakers are connected through the Jamma harness and the volume pot only controls the volume of the sound coming from the PCB going into the Jamma harness. In other words the volume pot isn't wired into the Jamma harness directly in any way so there shouldn't be any interference from it.
Exactly. Like I mentioned, the pots only purpose is to tell the MK PCB how loud I want it. It's not an issue with MKII since the pot isnt in use with MKII and volume is controlled VIA service menu.

Can anyone at least rule out my main PCB as a potential problem? I am really leaning towards the sound PCB. Maybe someone can test out my Sound PCB or even the whole boardset? The only other possible thig I can think of is I think I remember seeing a diode (or cap, maybe) or two in the speakers, Maybe MKII dosent use them?

I guess I should just quit being so damn cheap, suck it up and buy a whole other boardset with my fingers crossed, but I fear this could turn into a money pit if I take too many chances.
 
mk 2

i think mk 2 requires -5vdc on sound pcb while other mk 's may not , is the -5vdc connected to power supply?
 
I think we have a winner! well, maybe.

if MK2 DOESN'T have -5V, it makes a completely evil humming interference buzzing exorcistic sound.

and well, I don't hear that. welove80s, check your -5V pin on the JAMMA edge, make sure that's even hooked up, or check the PSU itself.

I don't think Midway would be total bastards and leave the -5V pin empty, but I can confirm from my MK1 manual that the -5V that's listed has a (not used) next to it.
 
All the voltages are good last time I checked. If you look at page 38 of this manual:

http://arcarc.xmission.com/PDF_Arca...rtal_Kombat_2_Kit_(16-44029-101 Oct 1993).pdf

Youll see pin 4 at P4 is marked +5v. Nothing seems to plug into it, and I can try putting 5v to it with no difference. Ive inquired on this pin before also and the best answer I got was possibly for a coin counter, so I'm back to square one, no sound.

Tonight I just tried tapping another speaker in, no difference. Then I just said screw it, removed the boardset and tried it in my Neo-Geo, still no sound. I think I can safely blame either board at this point, the question is which one, or both? Still leaning towards a bad sound PCB.
 
5

you mention +5vd, i am talking about the (minus )-5vdc, a few games use this, most dont, but mk 2 must have it
 
I only mentioned that because it seems like I cant get a straight answer as to what its for, but from what I gather it has nothing to do with sound.

Heres the voltage readings from the Sound PCB.
 

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If you hook the ribbon cable up backwards for a short while it won't hurt anything. Reversing the power harness would hurt it. If you want I can snap a picture of my cab later so you can see where the ribbon cable is flipped the other way. My sound does work. I had this same problem the first time I bought a MK2 pcb.
 
If you hook the ribbon cable up backwards for a short while it won't hurt anything. Reversing the power harness would hurt it. If you want I can snap a picture of my cab later so you can see where the ribbon cable is flipped the other way. My sound does work. I had this same problem the first time I bought a MK2 pcb.

OK, just tried that, no difference. Still no sound.
 
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