Building an arcade supergun, the right way.

There's plenty of guides out there suggesting that when building an arcade supergun you power the pcb using a computer power supply. This is a terrible idea. Some pcbs are very sensitive about the voltage used, also some pcbs require -5v which most computer psus don't have. I bought a cheap arcade power supply that has -5v and adjustable voltage. After turning the voltage to the left a little (I assume that turns it down) suddenly all the pcbs that used to reset and sometimes not boot were working every time. It's very important to use a power supply with adjustable voltage otherwise some arcade boards either won't boot or will randomly reset or both.

....and if you turn the screw the other way too much they go Poof. been there done that.

actually, the Big Neo geo boards like pc power supplies.

i had one hooked up for years to a power supply i modified with no issues at all. eventually i got tired of the neo and stuck a pc in it instead.

mvsfan wrote:

....and if you turn the screw the other way too much they go Poof. been there done that.

actually, the Big Neo geo boards like pc power supplies.

i had one hooked up for years to a power supply i modified with no issues at all. eventually i got tired of the neo and stuck a pc in it instead.

I actually turned the voltage adjuster as far as it could go both ways, nothing went *poof*. They don't let you adjust it far enough to cause any actual damage haha.

Drakon wrote:

mvsfan wrote:

....and if you turn the screw the other way too much they go Poof. been there done that.

actually, the Big Neo geo boards like pc power supplies.

i had one hooked up for years to a power supply i modified with no issues at all. eventually i got tired of the neo and stuck a pc in it instead.

I actually turned the voltage adjuster as far as it could go both ways, nothing went *poof*. They don't let you adjust it far enough to cause any actual damage haha.

you must have a *good* power supply. I turned the screw up and it blew a Contra Pcb. the sound progressively got higher pitched until... Nothing.

Drakon wrote:

There's plenty of guides out there suggesting that when building an arcade supergun you power the pcb using a computer power supply.  This is a terrible idea.  Some pcbs are very sensitive about the voltage used, also some pcbs require -5v which most computer psus don't have.  I bought a cheap arcade power supply that has -5v and adjustable voltage.  After turning the voltage to the left a little (I assume that turns it down) suddenly all the pcbs that used to reset and sometimes not boot were working every time.  It's very important to use a power supply with adjustable voltage otherwise some arcade boards either won't boot or will randomly reset or both.

Sorry to bump an old thread.

This is absolutely true. A lot of people won't hear it and claim it is complete bull$hit and use craptastic generic PC power supplies with their MVS. A youtube video of guy claiming this comes to mind.

You can use a PC power supply with the MVS. The issue is that MVS motherboards are OLD. When you are using something old you do not want to put any unnecessary stress on it at all. Using a PC power supply or worse, a wall-wort AC adapter, puts a lot of unnecessary stress on very old components. It isn't wise.

Even good PC power supplies don't necessarily have good 5 volt rails, they have good 12 volt rails for video cards. And none of them have adjustable voltage.

Finally, PC power supplies aren't cheaper than adjustable power supplies, so there is absolutely no reason to use one with an arcade PCB what-so-ever.

If we were talking about a $20 console, I might not be so adamant about using a Jamma power supply. However, a working Neo Geo MVS, with the upgraded BIOS, and all components needed to play games is not cheap and isn't going to be cheaper in the future. The same goes for Capcom CPS boards, etc.

As far as "turning the knob all the way to the left" and frying a board, I'm sure you can do that with some Jamma power supplies. That is what multi-meters are for. I'm not trying to be a jerk, but randomly turning a voltage adjustment knob all the way to the left isn't much different than dropping a PCB out of a window. The person doing it has to be aware they are likely going to damage something.

No need to apologize I don't mind at all when people bump something.  It's not like you were here when this thread was originally posted.

If you read my above post turning the knob all the way didn't fry anything.  I didn't play with it on an expensive pcb just a cheap one. Therefore I argue that it's not the same as throwing the pcb out the window.

Drakon wrote:

No need to apologize I don't mind at all when people bump something.  It's not like you were here when this thread was originally posted.

If you read my above post turning the knob all the way didn't fry anything.  I didn't play with it on an expensive pcb just a cheap one.  Therefore I argue that it's not the same as throwing the pcb out the window.

I was actually talking about the guy who fried his Contra PCB, which can run for $200. I should have quoted "turn the screw the other way too much they go Poof" instead of quoting "turn the knob all the way the left".

On my Jamma power supply I hook up a multimeter and turn the knob until it hits 5 volts on load and then leave it. Experimenting with inexpensive things is fine, but experimenting with something valuable and then blaming the consequences on the equipment is questionable.

And to be clear, I'm not being condescending to MVSFAN. I just don't necessarily agree with this line of reasoning on the quality of a good Jamma power supply. I know other people, like MVSFAN, who use a standard ATX power supply with their Neo-Geo MVS and they report no problems.

I just don't see the ATX power supply as ideal and as my MVS is a bit old, I'd rather use something designed specifically for Arcade PCBs that does not distress the motherboard.