Mortal Kombat II Soundboard help

Long Hair

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Here's the deal, I have sound in game,but not hearing anything when the attract screens are going, and no coin up sound. When I first received this board the chip under the big heat sink (on soundboard) needed to be re solder, after that I had sound off and on in the attract screen. But now I don't, and I have never seen the red led light up on the board. When the game boots up I get one dong,so that tells me the soundboard is working. Also I dumped all the rom chip's and checked them in winhex, and they match with the mame roms. Could this be a bad IDE cable ? And when should the red led light up? I was thinking at boot up, but have never seen it do anything. Thanks: Long Hair
 
just some thoughts to stimulate your diagnosis..

I never thought of it this way, what would happen if you ran it WITHOUT the ribbon cable, would it still just play the BONG! sound on power up?

if you say you resoldered a chip on the heatsink, that's the amplifier. obviously wouldn't hear anything if that wasn't working. okay.. the wiring harness that goes between the main board and sound boards is the one that carries power to the sound board (+5, +12, -5 and grounds) and it has the blue and violet wires if I recall, those connect to the speaker output at the JAMMA harness.

the ribbon cable will connect to headers on the main and sound boards, and both headers will have numbers on the pins like 1/20 and 19/20. very easy if you're not paying attention to confuse the 19/20 as a 1/20 based on what I've seen in past threads here. the red striped edge of the ribbon cable needs to be aligned with the 1/20 on both sides. verify this first (with the power off if you do need to flip it around). then go into Test mode, go under Diagnostics and then Sound Board Test. if it says something like "SOUND IRQ NOT DETECTED" then you don't have signal between the main board and sound board. if it says "SOUND IRQ OK" then you should have working sound.

now another thing that you could check, based on personal experience... is the game roms on the main board located at UG12 and UJ12. my game was sold to me as working, and it would work, until the one time it wouldn't and all I heard was the Wasteland music and baby crying sounds. even though all my connections were good, I was still getting the "SOUND IRQ NOT DETECTED" error, despite the game playing sounds, albeit, wrong sounds. when I pulled the UG12 and UJ12 roms I found 2 chips that were plastered in corrosion. Broodwich and I will then famously say.. get the fine grit sandpaper out and start grinding that crud off. :)

beyond that, I'm going to say it's a good sign you're getting the BONG! sound on power up. means your amplifier works, your speaker wiring output works and... your sound board for the most works I'm guessing. start by checking the ribbon cable. if you want to swap another in, you can use a computer IDE cable, even one that has a key in it, because one half of it will have 20 pins. if no key though, and your cable doesn't have a red stripe or equivalent, just draw along that edge with a sharpie and consider that your pin 1/2 side and connect it accordingly.

hope this all helps.
 
Dude, captain obvious moment...

Check that your volume isnt turned all the way down lol.
 
Dude, captain obvious moment...

Check that your volume isnt turned all the way down lol.

The Volume is @ 50%, Like I said I have good game sound, but no coin up or attract sounds. On the audio test screen(service menu), If I'm reading it right I should only hear 1 bong. Which I do,so I'm going to switch the ide cable(20 pin) with my Mortal Kombat, and see if that helps. Thanks for the info
 
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Those sound boards are noorious for bad solder joints try reflowing the board. I did one that had no bong and no red light now everything is running as it should. Red light on sound board comes on at bootup when you hear the bong sound.
 
Those sound boards are noorious for bad solder joints try reflowing the board. I did one that had no bong and no red light now everything is running as it should. Red light on sound board comes on at bootup when you hear the bong sound.

funny i was eye'ing a few of the solder joints on the one i have that's been giving me issues before i packed it up somewhere. I'll definitely have to go over them next time i'm messing with it.
 
I have a new ? There a cap @ C34 a 2200uf@16v. My ? is should I be seeing voltage on the top of the cap. I was getting a reading of 7.4volts, is this cap bad or is it normal to have voltage running throw the case of a capacitor. Thanks: Long Hair.
 
The red light on the soundboard should be on. Just a suggestion, are your dip switches set to enable the attract sounds?
 
I have a new ? There a cap @ C34 a 2200uf@16v. My ? is should I be seeing voltage on the top of the cap. I was getting a reading of 7.4volts, is this cap bad or is it normal to have voltage running throw the case of a capacitor. Thanks: Long Hair.

So is this a problem, or is it normal?
 
my god. you meter caps from the top? how did I not know this? LOL

what's your return on those, the cold ground?

and I never delved that far into that stuff so I can't really contribute much else. sorry boss

silly, but did you check all your voltages?
 
Sound test shows "SOUND IRQ OK".

The red light on the soundboard should be on. Just a suggestion, are your dip switches set to enable the attract sounds?
You were right about the dip switch, must of move it :eek:. So I have attract sounds again, but after a little bit they disappear.

Check my voltage all good, but the -5 reading about -3.3, maybe a problem but I have sound so I don't know. Going to remove all chips and hit them with some sand paper, I know for sure some of them need it. I'll try to test the LED to make sure it works. Still no Coin-up Sound.:confused:
 
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I've had two MK2 boards. Neither has played a sound for inserting a coin (MK 1 does, however).

I just plugged my current board into my cab and tested... no coin-up sound, but just to be safe I tried three different versions in the current build of MAME.... no coin-up sound there either.

Maybe someone else with a board can prove me wrong, but I'm positive there isnt' supposed to be a coin-up sound on MK2. I can also verifiy that the loss of attract mode sounds is correct.

Brian.

Sound test shows "SOUND IRQ OK".

You were right about the dip switch, must of move it :eek:. So I have attract sounds again, but after a little bit they disappear.

Check my voltage all good, but the -5 reading about -3.3, maybe a problem but I have sound so I don't know. Going to remove all chips and hit them with some sand paper, I know for sure some of them need it. I'll try to test the LED to make sure it works. Still no Coin-up Sound.:confused:
 
Well, after seeing what you guys have posted. I'm going to say that my soundboard is o.k. I checked the LED and could not get it to light up, so I put a known good one in. But still not lighting up, maybe I put it in back words who knows. Anyways thinks to all for the help. "GAME ON"
 
MK1 boards are real drama queens about -5v (which is used by the audio board), if you get -3.3v in reading, there's your problems. There's a guy on youtube that does a demo video on how MK1 board reacts with unstable voltages.

And since MK2 boards are using a variant of the Mk1 boardset, your problem might there. Try it with another power supply that you know that is good!
 
MK1 boards are real drama queens about -5v (which is used by the audio board), if you get -3.3v in reading, there's your problems. There's a guy on youtube that does a demo video on how MK1 board reacts with unstable voltages.

And since MK2 boards are using a variant of the Mk1 boardset, your problem might there. Try it with another power supply that you know that is good!

That'd be me...

 
I'll echo the attract mode sounds statements. You only get a few cycles of attract sounds after a game is complete, and then the game falls silent again until someone plays a game again. It will not play them again until you end another game.

I thought mine was broken too, for a bit.
 
everyone thinks that's a glitch or a problem, but that was pretty standard for any Midway game of that era. the only thing I would equate to being a software glitch is the lack of coin-up sound, every so often you might hear a trace of the "excellent!" (you'll hear like "e-" and it cuts out). I know this because we had this game waywayway back in the day when it was fresh and saw enough quarters get dropped in it, some being my own lol

also worth noting in the event of an absence of -5V this game makes the scariest buzzing and humming sounds ever.

from what I'm reading, that's all normal behavior. just play the game, don't worry about attract mode sounds. :) if you're only getting one BONG! on startup then that means a) your sound hardware is working and b) you have no rom errors on the sound board.

although your -5V does sound pretty low. in the very least I think that will cause your sounds to not be as loud. you running one of those grey Peter Chou power supplies by chance?
 
Those sound boards are noorious for bad solder joints try reflowing the board. I did one that had no bong and no red light now everything is running as it should. Red light on sound board comes on at bootup when you hear the bong sound.

funny i was eye'ing a few of the solder joints on the one i have that's been giving me issues before i packed it up somewhere. I'll definitely have to go over them next time i'm messing with it.

Got a chance to go over these tonight, and do some other tests.

No change at all. I reflowed the power/speaker +- header, the IDE cable headers, and a bunch of other ones and got no change. metered for -5 and was getting -4.97 (Red led stayed on the entire time on the sound board while testing).

I'm about to try throwing a amplifier chip as well as replacing all the caps on it next.

on this particular sound board all i get is humming and some faint screeching, i have a couple other sound boards tho that work fine with this main pcb so it's not the wiring or main pcb either.
 
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