MVS 6 Slot Dropping Sound

[FinalbossNYC]

I have a 4 slot Cab Running a Japanese 6 Slot MVS board and I've noticed that lately when in attract mode the sound will stop working , sometimes (rarely so far) it will have no sound at start up. The time duration is varied so I'm not quite sure if its some matter of the Caps heating up as I read in a thread somewhere a while ago. I haven't had it happen mid game yet, turning it off and on seems to be the current temp "fix". Also the guy I got it from had mentioned the speakers needing 2 mins to "warm up" to full volume which doesn't make sense to me but it is what happens. Any help would be much appreciated.

 

[MuppeT]

4 slots suffer from cold solder joints and trace burnout that lead to problems with the sound in many occasions. (not quite the one you are having though)
the remedy is usually to look carefully at the solder points on the bottom and if you some of them being a bit dark grey colored /dull and not shinny... you need to re-flow them.
Traces need to be looked at carefully.
Also check if the battery has leaked... even a little. if it had .. peal the cover on the bottom of the board around the battery and look for possible damage there.

 

[FinalbossNYC]

4 slots suffer from cold solder joints and trace burnout that lead to problems with the sound in many occasions. (not quite the one you are having though)
the remedy is usually to look carefully at the solder points on the bottom and if you some of them being a bit dark grey colored /dull and not shinny... you need to re-flow them.
Traces need to be looked at carefully.
Also check if the battery has leaked... even a little. if it had .. peal the cover on the bottom of the board around the battery and look for possible damage there.

Thanks Muppet, Ill take the board out this weekend and give it a once over, I haven't pulled the board out before since I've only had it a short time ill try and be ginger with it.

 

[skate323k137]

Yeah, check for cold joints, and if you have the patience/skill just recap the audio section while you're at it.

 

[FinalbossNYC]

Yeah, check for cold joints, and if you have the patience/skill just recap the audio section while you're at it.

I will thanks. I don know if I have the skill i haven't done this regularly in years also i have low confidence haha.

UPDATE
Took the board out someone clearly pealed back the RED label once you can see the tape they reapplied it with. The previous owner says wasn't him I believe him and I'm a sucker so theres that. here some pics I don't see any Leakage but I'm a Noob. theres a weirs pattern on under the battery itself (see pics). Whats the best way to clean the old sticker off better? and also could this be just a Speaker issue ? ( I suck at speakers) once again any help or comments are appreciated.

Also theres some ugly solder underside of the volume control slider area I'm not familiar with what does what on these boards.

 

[skate323k137]

Well the good news is that's not a stock battery, so it's been replaced, and doesn't appear to be leaking.

I doubt it's a speaker issue honestly.

Definitely have a look over the audio section (the section on the board with the most capacitors) and look for bulging caps or cold solder joints.

 

[madman]

Interesting, my 4 slot I used to have would do the same thing in attract mode, never during play. I assumed it was one of those multi-slot weirdness things like when you have certain games next to each other there are problems with switching between all 4/6 games.

 

[FinalbossNYC]

Well the good news is that's not a stock battery, so it's been replaced, and doesn't appear to be leaking.

I doubt it's a speaker issue honestly.

Definitely have a look over the audio section (the section on the board with the most capacitors) and look for bulging caps or cold solder joints.

Oh man thats good news !! Thanks so much for that info !
Heres the section I assume you mean, I believe they all seem good heres shots of the solder side as well. I might just drop fresh solder over all of it.

The last pic has a shot of the area under the volume slider does it seem kinda dirty or sloppy reflow job to you?
Thanks again for all the info.

Interesting, my 4 slot I used to have would do the same thing in attract mode, never during play. I assumed it was one of those multi-slot weirdness things like when you have certain games next to each other there are problems with switching between all 4/6 games.

Really? How long and often? My hasn't done it during play I just assumed it was only a matter of time.
Was your 4 slot a CMVS or in a Cab? Also did it ever resolve ? Was it only certain game line ups? And do you know anyone else this happened to? Im wondering if its a Large bit count issue . Any more info would be great , sorry for the machine-gunning questions. Thanks.

 

[skate323k137]

Yeah I'd probably take the time to use a little flux and reflow the area you mentioned, making sure the solder seems to take to the board and not just the "post." A couple of those joints look sketchy. Also those traces are easy to follow so bust out the multimeter on ohms and check the continuity to the next point on the trace.

 

[FinalbossNYC]

Yeah I'd probably take the time to use a little flux and reflow the area you mentioned, making sure the solder seems to take to the board and not just the "post." A couple of those joints look sketchy. Also those traces are easy to follow so bust out the multimeter on ohms and check the continuity to the next point on the trace.

Thanks again for the feedback Skate! I'm gonna do just that except I no longer own a Fluke meter so I can't check The traces but Ill remember that if this doesn't pan out. Can I bother you some more by asking if that Replacement Battery is one of those Super Capacity ones I read about that doesn't Leak, also what the hell is that little push button next to the blue dip-switches. Thanks again man.

 

[skate323k137]

I don't know a ton about 6 slots, so I don't know what the button is. Test button maybe? Not sure.

About that battery, if I'm not mistaken it's the same 1/2AA solder type I use to do CPS2 boards. It's not rechargeable, so you should follow this guide and remove the 470 ohm resistor next to the battery:

http://www.jamma-nation-x.com/jammax/tutorials.html#mvsbat6f (you'll probably have to click through the NEO GEO > MVS options on the side to get to the MV6F battery mod link)

As long as you clip that resistor that battery shouldn't leak, at least not for a long time.

 

[FinalbossNYC]

I don't know a ton about 6 slots, so I don't know what the button is. Test button maybe? Not sure.

About that battery, if I'm not mistaken it's the same 1/2AA solder type I use to do CPS2 boards. It's not rechargeable, so you should follow this guide and remove the 470 ohm resistor next to the battery:

http://www.jamma-nation-x.com/jammax/tutorials.html#mvsbat6f (you'll probably have to click through the NEO GEO > MVS options on the side to get to the MV6F battery mod link)

As long as you clip that resistor that battery shouldn't leak, at least not for a long time.

Thanks for the Link, I checked and its the same battery you described so I disconnected the 470 ohm res and then reflowed some of the solder on the spot I showed under the Volume control area. The boards were coated heavy in dust layers so I did the best I could to remove some of it with a can of air (not much good) and some Electronic cleaner but there is still some there.

While cleaning I noticed a trace leaving from the battery that looked sketchy maybe it was a repair ? Also it seems that maybe the battery was replaced as soon as the old one leaked as theres the slightest hint of a weird mark on the board where the battery lays ( both can be seen in photo below) .
Ive reinstalled the Boards and I'm currently running the 161 multi cart for the next few hours if nothing cuts out then tomorrow ill reinstall the 6 offical games I was running before.

Thanks again for all the follow ups Skate.

 

[FinalbossNYC]

UPDATE AFTER REPAIRS-
Sunday -I ran the Board from morning till night using only one slot occupied by the 161 in 1 cart I played it several times throughout the day and switched games 3 times. It Never dropped sound all day in attract mode or in game. In fact I could swear it sounded better (probably wrong).

Monday- I reinstalled the same 6 legit carts I had previously been running
1 Kof 98 683megs
2 Cyber lip 50Megs
3 Samurai Showdown IV 378Megs
4 Shock Troopers 2nd Squad 514megs
5 Aero Fighters 3 154Megs
6 Mutation Nation 54Megs

Ater 30mins of attract mode the sound dropped off.
I pulled Kof 98 and Moved SS4 up to the first slot and added Soccer Brawl 46Megs

The machine has been running perfect all day after removing KOF 98.

This whole problem could just be one of the incidents where certain games don't work in 4/6 slot machines together. Not long ago I had to pull Kof or Aero fighters I cant remember which but it was because Top Players Golf wouldn't show up with the other game inserted in the machine at the same time. Ive heard SNK released paper work on certain games stating this but i can't find the literature anywhere yet. Maybe we should start a Thread to list the game compatibility issues?

I would like to thank MuppeT, Skate323k137 and Madman for their input and help in solving this issue. Thanks Guys !