Neogeo mv1 sound problem help.

Westcb

Give an Azn, A Break Here!,
Joined
May 17, 2012
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1,190
Just picked up a mv1 today. I have a mvf1z now and when I switched the board I tried a few games and sounds are screechy, the neo start up sound was not jarbled but it's half the game sounds are coming through terrible. The board is switched to mono because I'm using a jamma connection. I did a little searching online and it recommended a cap kit. I went to test mode and it made the beeps fine, couldn't tell anything being different. I did for test try and switch to stereo for a moment on the board. It did get louder but not clearer so I powered down and switched back. Any ideas or does this sound like cap kit time to you guys as well? I certainly wanna exhaust all options before I start desoldering some 18 capacitors. Any help would be greatly appreciated thanks.
 

Xian Xi

JammaNationX,
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Screeching audio indicates possible broken connections to the Yamaha 2610 from the cart slot. I'd recap first since it needs to be done.
 

Westcb

Give an Azn, A Break Here!,
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Screeching audio indicates possible broken connections to the Yamaha 2610 from the cart slot. I'd recap first since it needs to be done.

I ordered a cap kit, I guess I'll put that in when I get the battery cell holders from you. It is leaking I saw the acid on the side, didn't notice any corrosion on the pcb thankfully. Not sure what/where the yamaha2610 is, do you have a recommended guide for this issue? I'll start googling now for it but if you have a resource I should check let me know. Thanks.
 

Westcb

Give an Azn, A Break Here!,
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May 17, 2012
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On an MV1 the YM2610 is right behind the battery near the back of the board I believe.

As for a pinout:

http://www.jamma-nation-x.com/jammax/tutorials.html?show=mvsym2610

The letters at the very left are the pin numbers on the MVS slot, make sure they are all connected. Obviously you will need to remove the big metal cart guide.

Finished the cap kit, did not change the audio problem. Started checking continuity and had a question. On the back of the cartridge slot I'm probing the a and b sets on only the first two sets? There is a A 1 thru 60 a B 1 thru 60 then another two labeled A and another B the first few points lines up it seemed getting a reading of .002 but then there were several that we're not working. I'm going to retest an write them down off the pinouts I got from your site. If I find some to be wrong can I run wire from those two points like I did on the 4 slot that had the battery destroyed traces?
 

Westcb

Give an Azn, A Break Here!,
Joined
May 17, 2012
Posts
1,190
Finished the cap kit, did not change the audio problem. Started checking continuity and had a question. On the back of the cartridge slot I'm probing the a and b sets on only the first two sets? There is a A 1 thru 60 a B 1 thru 60 then another two labeled A and another B the first few points lines up it seemed getting a reading of .002 but then there were several that we're not working. I'm going to retest an write them down off the pinouts I got from your site. If I find some to be wrong can I run wire from those two points like I did on the 4 slot that had the battery destroyed traces?

4 were not passing A49 a51 a52 a53
 
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