Audio Issues MVS Metal Slug 3

[r27blades]

Hi All,

Appreciate you taking the time to stop by and read. Recently got an MCS MS3 and noticed the game runs and plays well but is experiencing audio issues. No music and sound crackles and gets worse over time.

I attached a video link of what it sounds like and I attached photos of the boards. My assumption is I need to identify an issue with the boards themselves and while the traces and boards in general look clean and in good condition I did notice some of the contacts look at rough.

Any thoughts are appreciated. To this point I have confirmed proper 5V read out with a voltmeter, cleaned the contacts with 99% iso, took the cart apart and reassembled to make sure nothing was backwards.

Video link:
https://drive.google.com/file/d/1Z9sd4ek1o6pNGU3_Ltu3insZj-Ffbq18/view?usp=drivesdk

 

[NeoRocker]

Check that all standard ICs are still soldered properly and that you have no cold solder joints. Also use a magnifying glass or microscope to check the solder joints of the SMD ICs. Please provide pictures of the back sides.

 

[Neo-Alec]

Clean the cart and slots with a contact cleaner such as Deoxit, and reset the backup ram. If it's a multislot MVS board try taking out other carts and move it to a different slot.

 

[r27blades]

Clean the cart and slots with a contact cleaner such as Deoxit, and reset the backup ram. If it's a multislot MVS board try taking out other carts and move it to a different slot.

EDIT:

6Slot passes the Work RAM Test check screen for 10 minutes. In setup I also used A B C to do the RAM check. Sound issues still present.

Hi Neo-Alec, I am using a 6 slot and have tested with MS3 in different slots X. When you say reset the backup RAM is that something I can do through the MVH6 config menu?

 

[r27blades]

Check that all standard ICs are still soldered properly and that you have no cold solder joints. Also use a magnifying glass or microscope to check the solder joints of the SMD ICs. Please provide pictures of the back sides.

Hi Neo Rocker,

Here are the photos of the back. Looks normal to me but maybe you can identify something I can’t. Regarding the IC checks would you a reference tool I should use? New to this and unfamiliar with these boards. Assuming it is a matter of testing for tone from point to point?

 

[Neo-Alec]

Yeah, you can clear the backup ram by entering the hardware test menu, or by turning it on with all the dip switches on.

 

[r27blades]

So far I have continuity from the traces on the back of the board… the pins on the SMA and PCM look fine… not sure what to look for next.

 

[r27blades]

[UPDATE] Tested M-1 pins for continuity from front to back of board and also from trace side to contacts. All lines confirmed. So that’s good, I guess?

Started testing V 1-4. I quickly realized on the eprom side a pin hits multiple traces on the other side of the board. Which at first I thought I was on to something but if all 4 chips are holding the audio files it makes sense they are tied together…

Back to being stumped.

 

[r27blades]

Is there a way to tell if the M-1 or V chips went bad or have failed? Could they go bad even if continuity is present? These picture should be cleared of the boards and hopefully someone can see or suggest some thing I am clearly missing.

 

[Neo-Alec]

Is there a way to tell if the M-1 or V chips went bad or have failed?

You have to desolder the chips and read them in an EPROM programmer. It is a pretty common problem. My Irritating Maze cart is beat up, and had a V rom go bad.

 

[r27blades]

You have to desolder the chips and read them in an EPROM programmer. It is a pretty common problem. My Irritating Maze cart is beat up, and had a V rom go bad.

AH… I was afraid of that. Will need to do some research. Definitely out of my range and maybe out of my comfort zone.

 

[Neo-Alec]

Is the game expensive now? I would just return it or sell it to someone who can fix it and buy a new one.