Replaced my power supply, 12v too high

Noticed some noise in the video of my MV-1F, mainly on white screens. I could hear a little bit of a whine from the PSU so I replaced that. It cleaned the video up completely, but the 12v runs hot when 5v is properly adjusted. With 5v set around 5.1 at the PSU itself, 12v measures at 13v (12.99, but who's counting).

Anything easy I can do about that, or should I consider trying another PSU? The one I put in is a HAPP power pro.

Edit: audio seems fine, and before anyone asks the mandatory NOOB question, yes, I am measuring this with the PSU under load (board hooked up).

Set +5v closer to +5.00v.

And let the +12v line auto adjust it self.

The whine on white screens sounds to me like a chassis problem.

Ask Mistsurugi-w or arcade game what they think about it.

Replacing the power supply completely fixed the whine and video "noise," So that's really of no concern anymore. I put a PVM in there, so I knew it was not the monitor.

Even with 5 at 5.00, 12 is still at 13. Brand new PSU.

Weird. That's way too high for the 12V. Maybe there is something wrong with that PSU? You usually can't fine-tune the 12V line on the standard arcade PSUs. They should be pretty close to 12.0 out of the box. Mine runs at 11.99 on my brand new Happ power supply I just installed this past month.

Damn, yeah, 12v is not adjustable but usually varies correlating to the 5v setting. I have a similar PSU for the capcom IO on my NAOMI and 12v regulates itself just fine as long as it's under load and 5v is set correctly.

Maybe I'll just order another one. I really don't want to send this one back for a replacement, as it's the best I've got in the mean time, and I'm not trying to ghetto-rig an ATX PSU any time soon. I hit up the guy I bought it from asking if he can test one and send me a tested one, and I'll send this one back.

Usually it's a trade off, the higher the 5v level the lower the 12v line goes. The 12v line being 12.99v should cause any problems since most amps have a huge range of voltage anywhere from 5v-50v. I'd just run it on a smoke PCB for a few hours and then check the 12v line again.

Right on, glad you chimed in. I was wondering it would even be a big deal... it just runs audio anyway right? I can't see it being any "worse" than the 5v only mod.

I've ran it for a few hours and no issues... mind you this is the cab that was running 6 / 14 when I got it, and amazingly hadn't blown anything up. I'll re-check it when I get home.

Some KLOVers think it's not a big deal either, as long as it's not much above 13. http://forums.arcade-museum.com/archive/index.php/t-180864.html

It runs audio but some people tap the 12v line for coin lights and all that jazz. Also to note, some PSUs have an internal fan that run off the 12v line to both cool the PSU and provide the 12v line a minimum load.

Also you need to remember that the Happ Power Pro has a ridiculous amount of amps at the helm for 12v, 8 fucking amps. Overkill for most JAMMA games since 2A usually is more than enough.

So, just in case it's useful: I have the same power supply in my Neo (Happ Power Pro), and my voltages yield basically the same outputs. I wondered which would be more important as being spot-on -- I'll change my +5v to be closer to 5, and not pick something in the middle that's a compromise.

Just remember that the +5v line runs 99% of the logic on boards so it needs to be precise.

The one I got is only 2A on the 12v. I think my coin lights are pulling from the 12, but that's no big deal, those are working fine too.

I usually leave 5 at 5.1 when measuring directly at the PSU since that usually renders closer to 5.0 on the board itself. I learned that from http://forums.arcade-museum.com/showthread.php?t=215552

Like the post above mentions, always test at the board. That might be where some of the confusion lies in this situation.

Everything on the 12v line should have a high tolerance.

I wouldn't worry unless it goes over 13.2

skate323k137 said:

The one I got is only 2A on the 12v. I think my coin lights are pulling from the 12, but that's no big deal, those are working fine too.

I usually leave 5 at 5.1 when measuring directly at the PSU since that usually renders closer to 5.0 on the board itself. I learned that from http://forums.arcade-museum.com/showthread.php?t=215552

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Yeah, don't measure at the PSU, measure as close to the board as possible, either from the JAMMA pins directly, or from the harness connectors if necessary. You may not be getting 13V at the harness/board I'd still be freaked to run the 12V line that high, but I know there is a lot of room for error in a lot of this stuff. Hell, like you said, I've seen cabs running close to 6V on the 5V line with no issues, and these were on route places, so they were on all the time. Still, for my personal stuff, and I have some pricey boards, I'd want to keep power in check as much as possible.

skate323k137 said:

Replacing the power supply completely fixed the whine and video "noise," So that's really of no concern anymore. I put a PVM in there, so I knew it was not the monitor.

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Did this problem arise when you put the PVM in? If so, did your old monitor use an isolation transformer, and did you disconnect it when you added the new PSU? If the iso was still getting power, that could have been the cause of your video interference. They are typically shielded in cocktail cabs to prevent that sort of thing, but that's not always the case in spacious woody cabs.

Sadly I doubt this has anything to do with the 12v issue. Best of luck there!

RabbitTroop said:

Yeah, don't measure at the PSU, measure as close to the board as possible, either from the JAMMA pins directly, or from the harness connectors if necessary. You may not be getting 13V at the harness/board I'd still be freaked to run the 12V line that high, but I know there is a lot of room for error in a lot of this stuff. Hell, like you said, I've seen cabs running close to 6V on the 5V line with no issues, and these were on route places, so they were on all the time. Still, for my personal stuff, and I have some pricey boards, I'd want to keep power in check as much as possible.

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Measuring at the board showed a slight drop (as expected), but that meant I had to turn things up farther to get a solid 5.00 at the board. the 12v line is still 13.1 at the JAMMA edge. Unfortunately this PSU is not trading off (turning up the 5v also turns up the 12v rather than lowering it).

gabe said:

Did this problem arise when you put the PVM in? If so, did your old monitor use an isolation transformer, and did you disconnect it when you added the new PSU? If the iso was still getting power, that could have been the cause of your video interference. They are typically shielded in cocktail cabs to prevent that sort of thing, but that's not always the case in spacious woody cabs.

Sadly I doubt this has anything to do with the 12v issue. Best of luck there!

Click to expand...

Nah, the issue was visible on the old monitor too, even with the isolation transformer. I just thought it may have been the monitor (it's as old as me) and not the signal. When I put in the PVM I unhooked the isolation transformer, but the interference was still there. The PVM is powered straight from the wall, and I sent the mains to the new PSU directly as well to rule out any interference from the extra safety switch, power switch, etc. Baiscally it's AC mains -> PSU -> fuses -> board. I had both the faulty and new PSUs hooked up this way, and the new one cleared up the video. At this point with 5v adjusted correctly the video is flawless.

I'm thinking I'm not going to sweat having the 12v at 13 at this point. Sound is fine and clear, and 12v is within 10% anyway. I'd be a lot more worried about running the 5v with overcurrent, for the reason Xian Xi mentioned.