MVS Power Supply Issues?

Edit: problem was solved, it was a button all along.

I have a 2 slot MVS cabinet that wont play nice with a 161 in 1 multi cart, but I worry it might be a sign of other issues.

When I turn it on with the multi cart in, I get the green screen and it goes right to SNK vs Capcom. When I try to go back to the game selection menu it just does the same thing. I will occasionally see the game menu for a split second before it goes into SNK vs Capcom.

At first I thought it was the cart, but the replacement cart did the same thing. Then I suspected the board was the issue, but I tried a one slot board with a JAMMA to MVS adapter and got the same results.

After doing some searching, I saw some say that the green screen is a sign of a bad power supply giving low voltage to the 5 volt line, or just that the 5v needed to be turned up. I did sometimes see this screen on my regular single game carts. I got out my multimeter and took some readings. I couldn't easily get my probes on the edge of the board, so I had to measure at the harness as close to the board as I could get. I was surprised to see that I was actually getting 5.13 volts. Perhaps the voltage was actually too high. However, when I turned it all the way down it only went down to 5.09 and it didn't fix the issue. I tried going the other direction, up to 5.48, but there was no change. The 12 volt line read 11.96 with the 5v turned all the way down.

Obviously, its not the end of the world if I can't use a multi cart in my MVS. It would be nice, but I can live without it. My big concern is that this could be a sign of something that could affect the health of my board or other components in the cabinet. Any ideas? Could the power supply be the cause of all of this? Could the extra .09 volts be a problem, even though I've seen some on here say they run it at 5.2?

Get a Unibios 3.2 if you are using a multicart, they are design for use on single slots only with stock bios.

Also, 5.48v is too high, you can fry things when you go past the 5.25v threshold.

Thanks for the reply. I'm afraid the single slot board I tried didn't help. Yeah, I didn't leave it at 5.48, I turned it all the way down again. Freaked me out a little bit going that high.

Might be an issue with the cart itself if the power is looking good, and you've tried it on two different boards. I'd crack it open and look at the solder points as the build quality on these is poor.

GadgetUK suggests adding back the missing AMS1117 votlage regulator to the 161's board. You might as well recap it while you're inside. There are four 47uF16V caps inside, and you can replace them with bigger 30V or 50Vs. 47uF100Vs barely fit, so I wouldn't recommend going that high.

I have no idea if these mods would fix your particular problem, but they might give your 161 a better tolerance for voltage drops/spikes.

Also, do normal carts work fine in your MVS?

The voltage regulator won't help with that probably - It's just required to limit voltage to the 3.3v logic on there. This is a good example where overvoltage can help kill the NVPROM chips though. At 5.48v the NVPROMs are being overvoltaged by 0.75v, which is ~22%. Regards the voltage rating of the caps, are you talking about the inside of the cart? If so, changing those isn't likely to help. It's more likely to be the BIOS as Xian Xi suggests, or just a dodgy cart that has either a fault or poor connection on one of the chips. With some multicarts you only have to look at them the wrong way and they flake out!

SmokeMonster said:

GadgetUK suggests adding back the missing AMS1117 votlage regulator to the 161's board. You might as well recap it while you're inside. There are four 47uF16V caps inside, and you can replace them with bigger 30V or 50Vs. 47uF100Vs barely fit, so I wouldn't recommend going that high.

I have no idea if these mods would fix your particular problem, but they might give your 161 a better tolerance for voltage drops/spikes.

Also, do normal carts work fine in your MVS?

Click to expand...

BTW, I didn't suggest that for this issue

Fygee said:

Might be an issue with the cart itself if the power is looking good, and you've tried it on two different boards. I'd crack it open and look at the solder points as the build quality on these is poor.

Click to expand...

That was the first thing I tried. Replacement cart from a different store had the same problem.

SmokeMonster said:

GadgetUK suggests adding back the missing AMS1117 votlage regulator to the 161's board. You might as well recap it while you're inside. There are four 47uF16V caps inside, and you can replace them with bigger 30V or 50Vs. 47uF100Vs barely fit, so I wouldn't recommend going that high.

I have no idea if these mods would fix your particular problem, but they might give your 161 a better tolerance for voltage drops/spikes.

Also, do normal carts work fine in your MVS?

Click to expand...

Windjammers and Bust a Move seem to work fine.

GadgetUK said:

The voltage regulator won't help with that probably - It's just required to limit voltage to the 3.3v logic on there. This is a good example where overvoltage can help kill the NVPROM chips though. At 5.48v the NVPROMs are being overvoltaged by 0.75v, which is ~22%. Regards the voltage rating of the caps, are you talking about the inside of the cart? If so, changing those isn't likely to help. It's more likely to be the BIOS as Xian Xi suggests, or just a dodgy cart that has either a fault or poor connection on one of the chips. With some multicarts you only have to look at them the wrong way and they flake out!



BTW, I didn't suggest that for this issue

Click to expand...

Replacement cart had the same issue. Btw, I didn't leave it at 5.48 volts, only tested it briefly at that voltage. The lowest the PS will go is 5.08-5.09.

ShaunRF said:

Windjammers and Bust a Move seem to work fine.

Click to expand...

I asked because I had a stuck button on the arcade stick that I was building and it caused my MVS to boot straight into SNK vs Capcom with the 161 inserted. I had simply used the wrong ground terminal on one button. I hope that you find an equally simple solution to your problem.

That would certainly be nice. I'm starting to wonder if that extra .09 volts is the source of my problems and the only solution is a new PS. I'll have to figure out the best place to get one. Perhaps a store or site that can ship fast to Minnesota, as I would love to have the multi cart working this weekend.

ShaunRF said:

That would certainly be nice. I'm starting to wonder if that extra .09 volts is the source of my problems and the only solution is a new PS. I'll have to figure out the best place to get one. Perhaps a store or site that can ship fast to Minnesota, as I would love to have the multi cart working this weekend.

Click to expand...

I'm fairly certain 5.09 would not cause you issues, but definitely not saying psu is not the problem. I guess the best and most cost effective solution would be to try that cart on someone else's mvs board. Are you in a area where you know anyone else with a cab you can throw it in to test? If it's the original power supply it might be worth changing out anyways. I have had two neo psus finally give out in the last couple years and judging by age they had a decent run :-)

Westcb said:

I'm fairly certain 5.09 would not cause you issues, but definitely not saying psu is not the problem. I guess the best and most cost effective solution would be to try that cart on someone else's mvs board. Are you in a area where you know anyone else with a cab you can throw it in to test? If it's the original power supply it might be worth changing out anyways. I have had two neo psus finally give out in the last couple years and judging by age they had a decent run :-)

Click to expand...

Trying a different board was the second thing I tried. Got an MV-1B with a JAMMA to MVS adapter, but got the same result.

ShaunRF said:

Trying a different board was the second thing I tried. Got an MV-1B with a JAMMA to MVS adapter, but got the same result.

Click to expand...

If you are saying you got the same result with a different 161 in 1, and a different MVS then it must be your wiring loom or button inputs. I wonder if a button is stuck down causing the game to auto launch? I think it's very unlikely the PSU would cause the issues you are getting.

ShaunRF said:

Trying a different board was the second thing I tried. Got an MV-1B with a JAMMA to MVS adapter, but got the same result.

Click to expand...

Yeah trying a different setup is what I meant, so then you can narrow down if it's the cart. As mentioned if you have any shorts in your wiring it could very well be loading a game without you pressing a button. I'm assuming svc is game 1 on the list right? Since you tried different boards then you are down to the wiring, psu, and cart. Sounds like you changed the cart already, and your readings are within tolerance on the voltage, so might be worth a quick check on the wiring but it will be hard to rule out the cart until either you try a known working multi cart or try that cart in another setup. It's not full proof but you could go into input test and watch to see if anything is stuck showing closed circuit rather then open as it should be.

Wow, I am an idiot! Someone in another thread a while back suggested I go into the test screen and see if all the buttons were working. I never thought much of it because I wasn't noticing a problem in the two MVS games I own. I just went into the test screen and player 1 B button was sticking. I took the button off and one of the plastic tabs that pushes against the switch is broken off the button, so it needs to be replaced. I stole the D button from player two and its working fine. Still wont work with Windjammers in Slot 2, but thats not a huge deal. Thanks for your help everyone

Next question: where can I get a button fast? haha. There is a vending machine and gaming(mostly pool tables and dart boards) place here in Rochester called D&R Star. Hopefully they carry simple stuff like this.

ShaunRF said:

Next question: where can I get a button fast?

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Awesome news! Glad you got it fixed.

I doubt you'll find anywhere locally that carries them. Can you super glue it, or use Epoxy putty to rebuild the tab? If so, that would hold you over until the replacement comes in.

SmokeMonster said:

Awesome news! Glad you got it fixed.

I doubt you'll find anywhere locally that carries them. Can you super glue it, or use Epoxy putty to rebuild the tab? If so, that would hold you over until the replacement comes in.

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I don't know if I would trust stuff like that with a piece of plastic that is so small. I went ahead and ordered one off the Suzo Happ North America site. I ordered priority shipping and its coming from Illinois. It wouldn't tell me the shipping cost at checkout, so I might be paying out the ass to ship a 3 dollar item, but such is the cost of procrastination lol.

ShaunRF said:

I don't know if I would trust stuff like that with a piece of plastic that is so small. I went ahead and ordered one off the Suzo Happ North America site. I ordered priority shipping and its coming from Illinois. It wouldn't tell me the shipping cost at checkout, so I might be paying out the ass to ship a 3 dollar item, but such is the cost of procrastination lol.

Click to expand...

Might as well splurge and buy all new buttons :-) glad you got it working.

Probably will at some point. Although some of them look fairly new already.

Just in case anyone is curious, that local place did have the buttons I needed, although they only have the buttons with the horizontally mounted switches. Thats just fine by me though, because one of buttons that came on my MVS is a horizontal and I think it feels better. Also, the brand new vertical button I bought directly from Happ is sticking already.

The only issue with the local place is that their warehouse VERY dusty, so the parts look kinda gross and will need a good scrubbing. I only bought enough for one side. Will probably get the rest from Suzo Happ directly.