jamma board sound issues (got sound, still issues though..any suggestions?)

[NGT]

I can't get a jamma game to put out sound on my cab. I just wired up the -5v and it works on another jamma board but not too loud. Then when I put in the game I actually want to play, I get no sound.

The board puts out sound just fine on my mas supernova, but I get nothing from my cab.

any ideas?

 

[ttooddddyy]

Volume up
Dip switch for attract sound on

What board is it ?

 

[NGT]

Daraku Tenshi...and I don't know how to turn the volume up. It plays at a fine level on the supernova...why would it be different on the cab?

I could have sworn I saw something about volume adjust on that board, but I couldn't find it again when I went hunting. One of the reasons I would love to get my hands on the manual.

 

[NGT]

found the volume adjust...still no sound on the cab. But on the supernova the sound goes up and down just fine.

any ideas?

cleaned the jamma edge...still nothing

 

[NGT]

I also noticed that I can't get the game options menu on my cab but I can get in on the supernova via the test button or whatever.

does this give you any ideas?

 

[gt6plus]

Is your cab harness wired the same as your Supernova?

 

[norton9478]

Just a shot in the dark...

Does this board require a SOund amp (Like MK games)???

 

[NGT]

The supernova doesn't have a sound amp does it? UNless there's one built on the video converter.

 

[arcadecalgary]

just a question , are you getting +12 i belive this is required to run most jamma sound

 

[SeaWolf69]

Well,

You might have to wire in another in the test switch on your harness, what is your harness wired for? Also, some Jamma boards I found has to have the volume adjusted in the test menu? I could be wrong, worth a shot, I would check to see if your cab is wired for JAMMA or MVS?

 

[ttooddddyy]

just a question , are you getting +12 i belive this is required to run most jamma sound

good point

I read this like. other boards work ok in the cab, not the super nova.
No or low 12 volts - no sound

 

[Asure]

Is the cab wired for MVS multislot stereo perhaps ?

 

[NGT]

ok, so I check it and audio ground is not used on the harness and there is a pink and brown wire going from the L and 10 pins...then in the back, there's a molex plug that has the pink and brown wires and two black wires running through it.

So that looks like stereo sound to me....

But then why would the stv, pgm, aw, cps2, and other jamma games all get sound?

Would you suggest putting in a mono/stereo switch? I have done this in superguns so I am fine on doing the work. Should be pretty easy. But, if you don't think that's the issue, I dont want to do the work if I don't have to.

think I am on the right track?

 

[NGT]

Ok, so I put in the mono/stereo switch and got sound. But, there is a hum...

(no hum with another jamma game (crime city) or mvs in stereo...pgm gets no hum in jamma either)

also, the sound is great at first and then after a couple seconds gets softer. When I took the board out, there was a part in the front corner of the board that was hot as hell!!!

so I took the board upstairs and hooked it back up to the supernova and all is fine with the board. The corner did not get hot again on the supernova.

some of you said it might be a 12v issue....my 12v is at 5.3. Could that be too high?

any suggestions?

 

[NGT]

I turned down the 12v and the part that gets hot still gets hot. Why is it getting hot on the cab and not the supernova?


also, when I turn on the cab, there's a quick pop in the speakers and then the hum starts.


Something else I noticed was that the supernova sends ground directly from the power socket to audio ground on the jamma harness. The MVS setup has that wire going to the test button so no ground is going there. The part that gets hot on the motherboard has a screw there. Do you think that screw is for a ground wire? or should I put in a switch for audio ground to get ground directly to it like on the supernova?


Ok, so here's what I tried, I turned on the cab and held down the test button. This sends ground directly to the M pin and the sound stayed loud, sounded great, and the hum went away.....but, the part on the board still got really hot!!!

here's where the board gets hot (it's that black chip that heats up REALLY HOT! in the cab and not at all on the supernova) I do have a momentary switch on the test/ground for pin M, but I was holding it all the way down)

ANY SUGGESTIONS??????


Is that screw supposed to be grounded? If so, why would the supernova play it fine without that screw on there. I am thinking a straight ground to the M pin without going through the switch would be enough....what do you think? Anyone?

 

[MKL]

Forget about the screw and also forget about pin M: you probably read on that pdf on hardmvs that it is "audio ground" in the jamma pinout. That is misleading info: just ignore pin M when it comes to sound stuff.

In a jamma cab pin 10 must go to speaker+ and L to speaker-. If you plug a jamma board in an MVS cab pin 10 goes to speaker+ of the right speaker and so far so good. But pin L instead of going to a speaker- goes to a speaker+ as well (that of the left speaker) and that's not good, hence your problem...

Rewire the cab or add a switch.

 

[NGT]

on a jamma cab, can I use regular grounds for the speaker - and just have the speaker + split to the speaker + on the speakers when the switch is in jamma/mono mode?

or is it a must that speaker - is going to speaker - on the speakers ?



Also, why would that make the chip on the board heat up?

 

[ttooddddyy]

The audio output IC itself may be faulty

 

[NGT]

The audio output IC itself may be faulty

sorry....I edited my post after re-reading the post above.


I just don't get why it works fine on the supernova and that little chip doesn't heat up, but gets super hot on the cab....

When I hit the test button when booting up the board, the sound came on fine...

..but the chip still got hot.

any ideas?

 

[MKL]

It works on the supernova because that's a Jamma setup. And I guess pin M will not even be wired on that. If you make your cab wiring like the supernova wiring (i.e. standard Jamma) everything will be fine.

BTW the chip with the screw is the sound amp. And it gets hot for reasons already explained above.

 

[NGT]

The M pin is wired, put to the s-video out on the SN.


So let me get this straight....



For the game chip to NOT heat up and this stuff to work just fine...


I need to have the speaker - on the harness (L) split to the speaker -'s on the actual speakers.

Regular Ground wires going to the speaker -'s from the jamma harness are not ok and that is the reason that the chip is heating up.

But, the regular ground wires are fine for MVS stereo sound.


Is this right?

 

[MKL]

The M pin is wired, put to the s-video out on the SN.

??? I really don't understand this...Look, if you have a jamma board around, like CPS1 or CPS2, take a look at pin M, which is the 11th pin of solder side: you'll find out that it doesn't go anywhere on the board: it stops at the solder pad right behind the finger pin. So it has NO function and doesn't need to be wired to anything.

The other things you said are correct.

 

[NGT]

I must be mistaken somehow...

Thanks for your help!! I hope it works

 

[MKL]

An important thing: Jamma cabs usually have a single 8ohm speaker. An MVS cab should have two 4ohm speakers. If you want to get sound from both speakers then don't wire them in parallel because the resulting impedence will be 2ohm which is not good for jamma amps. If you wire them in series the resulting impedence will be 8ohm, perfect for jamma. However the wiring in series will mess up the MVS wiring I'm afraid...donno if it's possible to do all these things with a switch. Maybe it's better to use just one speaker for jamma...

 

[NGT]

damn...went out to work before I read that....

Here's what I did....


I have the speaker - and speaker + both split to the two speakers when the two switches are set to jamma.

I am new at this, so please bare with me.

What I did was wrong...right?

I now need another switch that totally disconnects one of the speakers?

Right now, I played the game and the amp didn't get hot like before....

The chip still felt a tiny tiny bit warm, but I am not sure if that's normal. It wasn't anywhere near the as hot as before...BY FAR!! and the sound was great!

But you are saying this still is bad for the amp? I really like this game and don't want to mess it up, so if I have to put in a third switch, I will.

oh, and this is a neo 25. The reason I wasn't sure about the wiring is because I was told it would play all jamma games fine....of course I have learned not to trust arcade infinity.