Metal Slug 4 strangeness

Hi

I got this MS4 cart that does strange things:

- When I use it on my AES, throught my MVS converter, it plays fine but the sound will randomly go out. After finishing the level, it comes back, but it goes out again after some time. Even while running the demo, the sounds go mute randomly. It's not always the same, sometimes the sound goes mute completely, others only the sound effects go mute.

- When used on my Omega CMVS, it plays perfectly always.

Now, I use these systems (the AES and the CMVS with lots of different carts, like 35-40 different games and this is the only one that causes any issue. I already tried cleaning it to no avail. This MS4 was bought NOS, so it's really clean and in great shape.

Any clues guys?

Thanks!!

Edit: I have the game running in constant demo on the AES, and noticed that the sounds start sounding distorted some times, like scratches and pops and screeches along with the regular sounds, but then will sound fine again...weird.

Sound cutting out completely is directly an M1 ROM issue, but I've never heard of the sound coming back. Usually once the M1 ROM makes the Z80 crash, it won't start again.

HeavyMachineGun said:

Sound cutting out completely is directly an M1 ROM issue, but I've never heard of the sound coming back. Usually once the M1 ROM makes the Z80 crash, it won't start again.

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Thanks for your help, HMG. I am thinking among the same lines, but I guess the sounds restart because when the level changes, there is some kind of reset on the music that forces the music program to work again. I could be wrong though, I do not have deep understanding of how the sound works on the Neo. Another thing I was thinking: Is there some difference that might cause the cart to crash on the AES but not on the MVS? both are UniBIOSED, ver. 3.1

Thanks!!

Edit: This is interesting. I took the memory card (NeoSaveMasta) out of the AES and it seems the game plays perfectly now. I already played three complete missions and the sound has worked with no issues. Any ideas? bug in MS4 or in the UniBIOS maybe? I ordered UniBIOS 3.2 a week ago, I'll see if upgrading to the latest version solves this.

When using a converter just remember that you are adding 2 more connections into the mix. MVS>Converter in>Converter Out>Console in. You need to keep everything clean, especially the converter and the system slot.

Xian Xi said:

When using a converter just remember that you are adding 2 more connections into the mix. MVS>Converter in>Converter Out>Console in. You need to keep everything clean, especially the converter and the system slot.

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Thanks James, however I've tried cleaning both, the AES slots and both connectors on the converter to no avail. I also tried the Metal Slug 4 that comes in the 161-in-1 cart and it works fine, that seems to point to the problem being somehow on my MS4 cart, however I see nothing wrong with it physically

100% sounds like a connectivity issue. Clean the contacts of that MS4 cart with a good de-oxidizing solution and contact cleaner. I feel like this is all I type into tech support these days, but alcohol doesn't do anything but remove surface debris. Chances are you have some slight corrosion on your pins that something like DeOxit will be able to remove in a matter of seconds.

RabbitTroop said:

100% sounds like a connectivity issue. Clean the contacts of that MS4 cart with a good de-oxidizing solution and contact cleaner. I feel like this is all I type into tech support these days, but alcohol doesn't do anything but remove surface debris. Chances are you have some slight corrosion on your pins that something like DeOxit will be able to remove in a matter of seconds.

Click to expand...

Thanks for your help, RabbitTroop. Here where I live they do not sell deoxit (at least not with that name). Does it have some kind of generic name or something to better identify it? I would like to avoid buying something that might damage the cart's boards. Or will any deoxidizing producto work?

Thanks a lot!!

aha2940 said:

Thanks for your help, RabbitTroop. Here where I live they do not sell deoxit (at least not with that name). Does it have some kind of generic name or something to better identify it? I would like to avoid buying something that might damage the cart's boards. Or will any deoxidizing producto work?

Thanks a lot!!

Click to expand...

Check your local electronic stores for a contact cleaner and deoxidizing solution. I'm sure there is something comparable you can find. Amazon sells DeOxit, I get this oiler bottle style which is really easy to use on the cart contacts. You can just squeeze a little on and rub with a cotton swab. If you're going to use an aerosol cleaner, just be very careful that you don't spray too much into the cart, or take the cart apart before cleaning. Years ago, I ruined the label of a minor/cheap game (luckily) because I didn't think about the contact cleaner flooding the cart and staining the label. So, if you're going to use something like that, spray the cleaner onto a cotton swab first, then use it.

RabbitTroop said:

Check your local electronic stores for a contact cleaner and deoxidizing solution. I'm sure there is something comparable you can find. Amazon sells DeOxit, I get this oiler bottle style which is really easy to use on the cart contacts. You can just squeeze a little on and rub with a cotton swab. If you're going to use an aerosol cleaner, just be very careful that you don't spray too much into the cart, or take the cart apart before cleaning. Years ago, I ruined the label of a minor/cheap game (luckily) because I didn't think about the contact cleaner flooding the cart and staining the label. So, if you're going to use something like that, spray the cleaner onto a cotton swab first, then use it.

Click to expand...

I just searched and found a contact cleaner from 3M in aerosol form, named Novec. I bought a can, should be here in about 3 days. I'll try it and report back how it goes. I hope it fixes the problems I'm having with my MS4 game.

Thanks for the help

Some MS4 copies have a cart edge that is about2-3mm too wide and when inserted into a slot are sometimes warped or offset. Measure it from left to right and compare it to another legit cart.

Xian Xi said:

Some MS4 copies have a cart edge that is about2-3mm too wide and when inserted into a slot are sometimes warped or offset. Measure it from left to right and compare it to another legit cart.

Click to expand...

Thanks for the tip, Xian Xi. In fact, I checked my cart and the char board was like 0.5mm wider than any other original char board. Che prog board was the same. I measured and filed it a bit and so far it has worked. i also cleaned the contacts with an electric contact cleaning product so no clue which of the two solutions was the one that worked but it seems to be fine now.

Thanks!!

aha2940 said:

Thanks for the tip, Xian Xi. In fact, I checked my cart and the char board was like 0.5mm wider than any other original char board. Che prog board was the same. I measured and filed it a bit and so far it has worked. i also cleaned the contacts with an electric contact cleaning product so no clue which of the two solutions was the one that worked but it seems to be fine now.

Thanks!!

Click to expand...

I tested the cart again today, same issue. I am afraid some of the chips inside it is bad, but no clue if it's the M1 or some of the V chips. If anybody has any clue what else can I check, it will be great.

Thanks!!

Edit: I noticed when the audio (either SFX, music or both) goes out, it makes a little pop noise. Maybe that gives some clue?

Edit2: I also checked the CRC of the game in both, my AES+converter (where I see the issue) and my CMVS, where the cart works fine. I got this:

With the CMVS:


With the AES:


Notice that one of the tests fails on the AES, on the CMVS everything goes OK, can that produce the issue with the music in the game?

Thanks!!

I know there's a code to change in game music: check jaraschyter yt channel (ms4 bugs vol.2).

gamerwhat said:

I know there's a code to change in game music: check jaraschyter yt channel (ms4 bugs vol.2).

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Hi

I couldn't find the part two of the MS4 video, only the part 1: https://www.youtube.com/watch?v=3GvSzzIc9h8

Regards.

Sorry yes, its on part 1, go to 22:20. Let me know if it works for you.

Hi

I finally seem to have fixed this by replacing the M1 chip. Got an EPROM, got the ROM, burned it, replaced it, voilá.

Thanks!!