My MV-4F became a 5v+ power hungry MONSTER!!! Help!!

Hi there!

I have a Unibios 4 slot MVS (MV-4F) that is playable via my Supergun powered by my fairly new SuzoHapp 150W PSU (+5V 15A, +12V 5.5A, -5V 1A)

It has worked great for the past 2 years or so but all the sudden, I have had to dial up the PSU (Little nob on the PSU to max settings) to nearly 5.82V for the MVS to not go into watch dog...

When its cranked to max settings, I can get into most games but other games (I.e matrimelee) it will boot to the game but as soon as I hit start it auto reboots to the unibios setting.

I don't want to damage the chipset by having the PSU cranked at max as recommended is ~ 5.2v+

Has anyone ran into an issue like this before?

Check your connection on the jamma connector. It sounds like a 5v is loose. On my board I had the same problem. You may want to resolder them. Also does your psu have more than one 5v out? Maybe two.. There are four I believe on a jamma connector. Don't wire them to the same output on the psu.

Oh, okay I'll give that a try and let you know if it fixes anything thanks! I'll keep you posted

Be careful increasing the voltage like that! I would be measuring the 5v somewhere on the top and bottom boards to make sure you aren't going far above 5.25v. If you feed 5.8v into some ICs they will die. Chances are the full 5.8v isn't reaching everywhere but it might be reaching some chips on the bottom board.

Hey GadgetUK!
I knew something was worrisome when I saw it needed more than 5.25v. Luckily I haven'y played it much in fear of killing any IC Chips. (Tbh, I am not even sure which surface mount IC would be causing this? None of them look burned or damaged)

I checked the PSU and it does not have any power loss, hook it up to the jamma edge and the 5v+ (Parts side) is reading the same as the PSU so no power loss.

I thought the same, like where is it the 5v+ getting dumped? Where could it be lost?

I did a cap kit on this PCB about 3 years ago and it has been working great with no issues and taking the recommended 5.25v+ with no issues but I took it out of storage (in storage for about 6 months) and bam! its like is a 5v+ hungry monster.

I am at a loss..

Any ideas where it could be getting dumped?

Oh pS @Hine62, I checked my supergun's wiring and the PSU/ Jamma 5v+ line had a solid connection and it was using one of the 5v+ lines from the SuzoHapp 150W PSU (+5V 15A, +12V 5.5A, -5V 1A)

Thanks you two!
I really hope we can figure out what is up. Appreciate your help

I would start by separating the top from the bottom board - see if the bottom board still needs more than 5v on its own. If something is consuming a lot more current you would feel it in temperature. Maybe the connections between the top and bottom boards are dirty - meaning the top board is getting less than 5v when the bottom has 5v.