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ATX bench PSU

invzim

invzim

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Time for an upgrade! My previous ATX bench supply was without me knowing it causing all sorts of video issues. After identifying the problem, it was time to get a new one, and I've picked up a Cooler Master MasterWatt 650W. ATX power for arcade is just fine, but using an old beat-up recycled thing may not be ideal unless you have a way to verify that is's working ok. A multi-meter will not do the trick unfortunately.

You're never going to need 650W, but the nice thing is that even with ~5A on the 5V rail, which is about as much as you will ever see - it stays quiet with no fan activity. Also nice with this one is that it doesn't have a ton of cables/connectors attached, and that the 24pin cable is a little longer than normal. The ad for it says 16AWG, which turned out to be bogus - the 24pin is plain 18AWG.

2019-02-13 cooler master 650.JPG

Scope time :)

This was the root cause of issues I had with the old one, ripple about 0.17V when loaded ~ 4A:
2018-12-31 moon patrol atx power ac couipled 5v.png

This is the cooler master, with a ripple of about 30mv, or 0.03V which is really good:
2019-02-13 moon patrol cooler master master watt 650.png

For reference, same setup with my linear Rigol DP831 fancy lab supply:
2018-12-31 moon patrol DP831 ac couipled 5v.png
 
Hi, I've some questions

The Cooler Master MasterWatt 650W you've picked up is a 80+ Bronze or 80+ Gold?

Is it working properly with most arcade boards?

I've tried to use ATX PSU (PC) for arcade board such as CPS2 but it doesn't work due to the voltage was dropped below 5V
and there is no adjustable.
 
I use a tiny Pico power supply with CPS2, no issues whatsoever. CPS2 only requires around 3 amp, strange your ATX wasn't adequate.
 
phoenix07 said:
Hi, I've some questions

The Cooler Master MasterWatt 650W you've picked up is a 80+ Bronze or 80+ Gold?

Is it working properly with most arcade boards?

I've tried to use ATX PSU (PC) for arcade board such as CPS2 but it doesn't work due to the voltage was dropped below 5V
and there is no adjustable.
Click to expand...
Exact model I got is "MPX-6501-AMAAB-EU", which seems to be bronze. I've had CPS2 on the bench with this, and no issues. It's so full of juicy caps that it often takes a few seconds for the power LED on the Jammafier to go dark when you turn it off.
 
For what it's worth, I also run an ATX power supply with a CPS2 (runs my entire cabinet including Lights, fan, audio amp, JVS IO and Jammafier) and have no problems at all.
It is a high quality one though, not a bargain bin supply. Seasonic X-650. Power supplies are the one thing you never want to cheap out on, ever, whether it's your computer or your arcade boards.
Bad power supplies will potentially cause weird issues at best, and at worst, kill whatever you have hooked up to it when it inevitably self-destructs.

Edit: Another cause of problems is undersized wiring. I see this a lot in the arcade world for some reason despite people being otherwise quite knowledgeable. Seeing things like running high draw boards and components through a single tiny 20awg steel or aluminum wire with the voltage output cranked 10%+ to compensate and other such nonsense quite worryingly often. With adequately sized wire for a given load and wire length, there should be very little reason ever, if at all, to ever adjust a power supply's output outside of spec.

IMG_9796.JPG
 
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Thanks for all comments, I will replace the old one with the COOLER MASTER MasterWatt 650W :)
 
I've had great luck with this particular PSU from Suzo Happ:
https://na.suzohapp.com/products/power_supplies/80-0002-10

Frank built me a cable that plugged straight out of it to an ATX connector.

The main point in me getting that PSU over an ATX was that the +5v is adjustable on the Suzo Happ which helped out on a few tricky boards (big stuff like M-72 but also smaller stuff like Cave CV-1000).

I believe @SmokeMonster uses a similar supply from Suzo Happ with good results too.
 
I use a SUN JVS (NAOMI) PSU on my bench, and I have the auxiliary connector wired to a JAMMA harness, it makes testing both JAMMA and JVS boards a breeze.

I've suspected it's been in need of a rebuild though. This thread makes me think I should run it though a scope.
 
twistedsymphony said:
I use a SUN JVS (NAOMI) PSU on my bench, and I have the auxiliary connector wired to a JAMMA harness, it makes testing both JAMMA and JVS boards a breeze.

I've suspected it's been in need of a rebuild though. This thread makes me think I should run it though a scope.
Click to expand...
After having a PSU explode in one of my cabs and spark before, I’m super careful now and send ‘em to Jomac here in Australia for a refurb before playing any cab I own. I just sent two off today actually.

Highly recommended action as the PSU is essentially the heart of the arcade and once they’re checked up you’ll rest easier pluggin’ in all your PCB nuggets ;)
 
djsheep said:
Highly recommended action as the PSU is essentially the heart of the arcade and once they’re checked up you’ll rest easier pluggin’ in all your PCB nuggets
Click to expand...
I inspect them when I get them, put a load on them and see how stable the voltage is at load and after a long use, but rebuilding every single one seems unnecessary, particularly since I've probably got 40+ PSUs kicking around.
 
I've tested with CPS2 board and I saw that the 5V was dropped to 4.62V and there is no video signal :(

I also tested with MVS and System-11 boards I got 4.91 and 4.89 respectively but they are working properly.

Any suggestion?

2019-06-17-114636.jpg


2019-06-17-114653.jpg


2019-06-17-114706.jpg
 
If your power supply has sense wires, make sure its tied to the they are tied to their respective supplies.
They're usually thinner versions of the identical supply wire. 3.3v is almost always present (and usually doubled with a supply pin). 5v can sometimes be present but isn't always connected like 3.3 is. Take a look at your 24-pin to see if any of this sounds relevant.
 
phoenix07 said:
I've tested with CPS2 board and I saw that the 5V was dropped to 4.62V and there is no video signal :(

I also tested with MVS and System-11 boards I got 4.91 and 4.89 respectively but they are working properly.

Any suggestion?
Click to expand...
Check the wiring between ATX power connector and jamma edge, continuity and type/number of wires. Not sure which device you're using to connect to the CPS2, it may not be optimized for power delivery?
Reference with the Jammafier, https://www.arcade-projects.com/forums/index.php?threads/name-for-jvs2jamma-board.4319/post-77030

I haven't measured actual power draw of CPS2, but will do so next time I have it out:
https://wiki.arcadeotaku.com/w/PCB_Power_Consumption
 
I connected my supergun using the wire with Molex 4-pin connector (included in the box) and it seems too long.

I can't connect with the 24-pin ATX due to my supergun doesn't support it.

I will try to make a shorter wire for Molex 4-pin but I don't know what is a type of PSU's connector

2019-06-17-140327.jpg
 
Using the 4 pin molex isn't any better. They're designed to carry 2.5 amps, no more.

You need to utilise the 20/24 pin ATX connector. It has appropriate gauged wire and a connector that can handle the current.
 
Frank_fjs said:
Using the 4 pin molex isn't any better. They're designed to carry 2.5 amps, no more.

You need to utilise the 20/24 pin ATX connector. It has appropriate gauged wire and a connector that can handle the current.
Click to expand...
For this particular PSU, that is not correct. The ATX is 18AWG, while the HDD wires are 16AWG. But yes, the more/thicker wires the better. The adapter I made for ATX->JST-VL and use with the Jammafier uses 4x5V from ATX with 18AWG, effetively 12AWG..
 
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