Mortal Kombat 2 Sound issues.

[paulcan2]

 
Hello people,
 I'm a member on arcade otaku, and on jamma+, have just not posted on here.
Please can anyone help with this...

Just got another MK2 sound card from the states hoping it would cure my slight fault and it's exactly the same, so now maybe my main board has a fault or it's the wiring??

Any ideas?

The fault is very slight but I know it's there compared to mame.

The overall sound is slightly distant and quiet, almost with a slight buzz/humming in the background.

When you put a coin in it should say "excellent"

It doesn't! 

But sometimes it does but very very quiet, all other sounds seem to be there and correct but I can tell it isn't right.

If you go into the test menu you can test the sound board, it comes up ok for it being present, but all roms say 'bad checksum  U2 etc..' which is why I got another one to check, but it is the same.

Maybe they are both faultly but my gut says it's something else.

This is the dcs sound system, not the yamaha one on the first mk game.

Could be my ribbon cable?? the replacement one I got was a board only no cables so all cables I used are the same.

Any ideas would be very kind, anyone got a ribbon cable I could borrow/try, I will pay you, and the postage.

Or would burning a new set of roms be an option? I can send you one of the sets?? Can these roms be burnt, "noooob question alert"

The psu said 5.1v, got that back to 5.0v

The sound board was 12.21v



Like I said it sounds ok, but should be clearer and louder (although it does go quite loud)



It says in the sound board test menu:-

GENERAL TEST

REVISION 3.1

LISTEN FOR TONES:

0 TONES - CHECK HARDWARE

1 TONE - SOUND BOARD OK

2 TONES - BAD U2 CHECKSUM

3 TONES - BAD U3 CHECKSUM

4 TONES - BAD U4 CHECKSUM

5 TONES - BAD U5 CHECKSUM

6 TONES - BAD U6 CHECKSUM

SOUND IRQ DETECT FUNCTIONAL

ANY BUTTON TO CONTINUE

 

Thanks Paul.

EDIT:- Both the sound cards I have do exactly this

Also just pulled my cmos battery out of my mk1 board (same battery BR2325) and the battery works and saves all the settings as it should now, but still all the same faults as above.

[Kevin Mullins]

How does your -5v look ?

MK2 absolutely requires a good -5v and I've seen power supplies have good +5v but low -5v.

[paulcan2]

Good call, no-one has metioned that yet. Thank you
I even measured 12 and +5 today but not -5V!!!
If it is bad there is no way to adjust -5v is there?
This means a new psu??

I posted on jamma+ forum as well, and I now understand that the test menu isn't telling me that the checksums are bad, it was just saying count the no. of tones, I have 1 tone which is correct and means it's all ok.

Some people said bad caps, which sounds about right, but both sound cards are exactly the same??
So your theory sounds more like it!!
Good call once again! I will measure in the morning, where's the best place to test it for an accurate result?
Or just off the psu will be fine?

Thanks
Paul.

[Kevin Mullins]

I will measure in the morning, where's the best place to test it for an accurate result?
Or just off the psu will be fine?

Check it at the PSU first, if it's off there it will most certainly be off at the board.
Generally you would want to check at the board itself. So if you get a good reading at the PSU then move and check it at the board.

Still no guarantee that's the issue, but worth taking a quick look at to know where it stands.
(since it would mostly effect the sound board)

I've seen MK2's where the PSU had to actually be turned up a bit above where you would normally see it. (+5 and +12) But usually they just don't boot correctly at all in those cases.

I have 1 tone which is correct and means it's all ok.

Correct ....... if you had MORE than one tone, then you would look for what is listed that matches the number of tones you hear.
1 tone is good.

[ste]

bumping a old topic here but i same problem as OP. ithink its bad caps i get no sound at all. anyone know how to recap a mk2 sound board ?
 

[ste]

sorry for double post but i found out whats wrong. i just tested all caps on board with multimeter they are fine. so no need to recap them.

the problem was the small cystal, it says JAPAN 10,000 KDS 3J on it. this thing was completely dead so i replaced it and now my mk2 sound board is working again.

i hope this can help anyone with problems but first test with multimeter.