MiSTer FPGA Forum

Recently I fucked up really bad. I am heartbroken about this self inflicted wound I've brought upon myself and I'll have to spend months saving money to fix it worse case scenario. This is gonna suck but here goes!

You guys are no stranger to the Neo Geo MVS console I'm sure. Although I've owned mine for quite sometime I haven't played it in a while and that break from the action caused me to forget things, now it's haunting me. I inserted a few games in my machine the wrong way... a few times. I forgot the cart needed to face front. That's on me, I've owned my CMVS for several years how could I forget something SO vital? It's a mistake I'm growing to live with. Once I've come to a solution I'm putting labels on all my future carts so this doesn't happen again! Of the games I inserted backwards 1 out of 2 no longer work, I tried another 2 carts and again 1 of 2 worked although the one I couldn't get working was fairly beat-up. Still I'm wondering if my CMVS is now damaging something in my carts or if it's the CMVS itself? Whatever the case I'm not putting anything else in there until I know what's wrong.

So basically I'm asking if this sounds like a hardware or software problem? Granted one of the games I inserted wrong no longer functions, the other game is dirty and looks like it's been in a warzone. There were three games I tried and they work great. A friend of mine wants to help so he's bringing by his MVS tomorrow to test it out on the broken games. He has like 4 MVS systems, he's not a tech guy though.

I prefer there being only an issue with the two games and NOT my hardware. Worse case scenario if it's the board itself can someone recommend me to someone who can repair a CMVS from Analogue and whether or not they do hard mods, such as new uni-bios and memory card? Say it is the board where might it be damaged? My best guess would be the cartridge connector.

i would have expected the cartridge to have notches to prevent accidental reverse slotting as has happened to you, but it seems it has not.

you could have a look at the pinout diagram and line up the pins that got reversed and see if might have accidentally put voltage on data or ground pins by the reversed slotting.
unless there was a high current flowing through those pins i wouldn't expect the cartridge slot to be defective unless it has burns marks?
what i would expect is that the chip(s) or cpu(s) that handle those lines got fried because a data line might have accidentally received a too high current.

i hope you can find a solution and that the problem can be fixed albeit easily.

MostroW wrote: ↑Wed Jun 30, 2021 7:23 am i would have expected the cartridge to have notches to prevent accidental reverse slotting as has happened to you, but it seems it has not.

you could have a look at the pinout diagram and line up the pins that got reversed and see if might have accidentally put voltage on data or ground pins by the reversed slotting.
unless there was a high current flowing through those pins i wouldn't expect the cartridge slot to be defective unless it has burns marks?
what i would expect is that the chip(s) or cpu(s) that handle those lines got fried because a data line might have accidentally received a too high current.

i hope you can find a solution and that the problem can be fixed albeit easily.

Yeah, I lack soldering skills. I'll learn it some day but in the mean time I'll have to send it to someone.

So your saying you think it's an issue with my console, not the games? Fuck.

i would have expected the cartridge to have notches to prevent accidental reverse slotting as has happened to you, but it seems it has not.

AFAIK none of the MVS games have this. If they only did I wouldn't even be in this mess because I would fear brute forcing the cart. The other reason why I wound up sliding it in backwards was on account of the carts fitting better backwards than they did forward, which threw me off and made me think that's how it's supposed to be. Hence I turned it on and thus created a mess. The whole thing was of course an accident. The me from 2 years ago would've known the only thing preventing a NGM owner from sliding the cart in backwards is the arrow in front. I just wish I remembered that a week ago before doing this.

Captain FPGA wrote: ↑Wed Jun 30, 2021 9:36 am So your saying you think it's an issue with my console, not the games? Fuck.

I can't say i'm 100% sure, but this is what i would expect.
Let's see if we can find a schematic of a typical cartridge / cartridge connector pinout, that could shed light on your current problem.

Looking at: https://wiki.neogeodev.org/index.php?ti ... dge_pinout for quick reference.

Unless i'm mistaken the board(s) flipped means:

CHA top => PROG bottom:

SDA15, SDA14, P2, P0 have contacted GND

CHA bottom => PROG top

P1, P3, SDD6, SDD7 have contacted GND

Luckily looking at the board the VCC on all boards are the 4 middle ones, so i wouldn't expect something to have been blown up, unless different voltages or too high current(s) on said part(s).
Also if you have a quick look at the cartridge definitions of the other lines, i cannot say whether things got burned by having the board in backwards.

For that i'd guess you'd need the schematic of the Neo Geo and know how of the used parts, to possibly tell what can be done to save your MVS.

I had Neo Geo MVS and I recall (could be wrong, just writing this as a hope that probably you haven't broken anything) that one cannot harm either the MVS board neither the game cartridges by pushing game wrong way in. It just won't boot. I do recall that the connectors in games and in the motherboard need to be cleaned quite well from time to time.

From memory a reveresed cart should have no effect other than not booting. Infact I know I've done it a few times and had no ill effects. It's possible the pins and slots just need a clean as you've transfered crap from non-essential pins. A cotton bud and isopropyl is a good place to start before you worry too much.1

wodmarach wrote: ↑Wed Jun 30, 2021 12:59 pm From memory a reveresed cart should have no effect other than not booting. Infact I know I've done it a few times and had no ill effects. It's possible the pins and slots just need a clean as you've transfered crap from non-essential pins. A cotton bud and isopropyl is a good place to start before you worry too much.1

Thanks guys your words are encouraging. Yeah, I don't think a thunderstorm was happening or anything when I did this. A current is possible but probably unlikely. I remember putting AOF in there 4 times, the one time I did it though it showed a sprite then white screen. Now I can't get it to show up at all.

It sounds like everyone here is saying I need to clean the cart slot, am I getting this right? Btw like I said it'll work for other games I inserted. The only problem games are AOF which I inserted too many times wrong and Shock Troopers 2 which to be fair I bought SUPER used and dirty.

From what I read, many NeoGeo cartridges have dirty contacts. Never owned one myself, but a quick look at google shows up many video tutorial how to clean the contacts of a NeoGeo cartridge. I would suggest to look some of them and then try to clean the contacts.

Captain FPGA wrote: ↑Wed Jun 30, 2021 8:46 pm It sounds like everyone here is saying I need to clean the cart slot, am I getting this right? Btw like I said it'll work for other games I inserted. The only problem games are AOF which I inserted too many times wrong and Shock Troopers 2 which to be fair I bought SUPER used and dirty.

Slot and Cart. You can open them without damaging the labels with a little care which makes it much easier to clean the carts. The contacts on the carts aren't the greatest so a gentle clean with a pencil eraser followed by iso' on a cotton bud should clean up most contacts.

wodmarach wrote: ↑Wed Jun 30, 2021 11:05 pm

Captain FPGA wrote: ↑Wed Jun 30, 2021 8:46 pm It sounds like everyone here is saying I need to clean the cart slot, am I getting this right? Btw like I said it'll work for other games I inserted. The only problem games are AOF which I inserted too many times wrong and Shock Troopers 2 which to be fair I bought SUPER used and dirty.

Slot and Cart. You can open them without damaging the labels with a little care which makes it much easier to clean the carts. The contacts on the carts aren't the greatest so a gentle clean with a pencil eraser followed by iso' on a cotton bud should clean up most contacts.

There MAYBE some good news to report.

My friend came by. Tried those same games on his unit and got the same behavior. Then I popped Shock Troopers 1 in his Neo Geo and I got a glitchy mess. I blew on it twice then it worked perfectly.

Popped the same game Shock Troopers 1 into my CMVS and got a loud buzzing noise. Took it out and reinserted it and now it even works on my system.

Maybe you guys are right and I do need to clean. The most I can clean is the MVS cart slot since analogues consoles cover most of the board. It's nothing for me to pop open the carts then clean, I opened my Neo SD Pro to flip it around so this is nothing.

followed by iso' on a cotton

What's an iso?

Captain FPGA wrote: ↑Thu Jul 01, 2021 2:01 am

followed by iso' on a cotton

What's an iso?

Isopropyl alcohol.

Captain FPGA wrote: ↑Thu Jul 01, 2021 2:01 am There MAYBE some good news to report.

My friend came by. Tried those same games on his unit and got the same behavior. Then I popped Shock Troopers 1 in his Neo Geo and I got a glitchy mess. I blew on it twice then it worked perfectly.

Popped the same game Shock Troopers 1 into my CMVS and got a loud buzzing noise. Took it out and reinserted it and now it even works on my system.

Maybe you guys are right and I do need to clean. The most I can clean is the MVS cart slot since analogues consoles cover most of the board. It's nothing for me to pop open the carts then clean, I opened my Neo SD Pro to flip it around so this is nothing.

Good to hear that nothing seems to have been damaged!

MostroW wrote: ↑Thu Jul 01, 2021 5:30 am

Captain FPGA wrote: ↑Thu Jul 01, 2021 2:01 am There MAYBE some good news to report.

My friend came by. Tried those same games on his unit and got the same behavior. Then I popped Shock Troopers 1 in his Neo Geo and I got a glitchy mess. I blew on it twice then it worked perfectly.

Popped the same game Shock Troopers 1 into my CMVS and got a loud buzzing noise. Took it out and reinserted it and now it even works on my system.

Maybe you guys are right and I do need to clean. The most I can clean is the MVS cart slot since analogues consoles cover most of the board. It's nothing for me to pop open the carts then clean, I opened my Neo SD Pro to flip it around so this is nothing.

Good to hear that nothing seems to have been damaged!

So I just did a thorough cleaning of both problem cartridge Shock Troopers 2nd Squad and Art of Fighting. I used a combination of both pencil eraser to clean the contacts that mate with the cartridge slot and iso' for the rest of the board. All games are now working, thanks to the wonderful advice you all provided!