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Hello, had no problems at all with the power supply to my Astro City or PCB's. Today I put Mortal Kombat II in and I got no sound. Since I already knew this from my Supergun / MAK was clear to me problem with -5v. Then I measured and yes on the -5v Pin i got +0,67v. rest is normal +12v and +5v

Took pictures, where do I look, what could be the reason ?

Thanks
Same things happened in my NAC cabinet + 400-5198-01X psu , only on my -5V line i get -3.12v maximum and i dont have sounds in Rastan or MK2 pcbs

On my Astro City 2 cabinet + 400-5220 ,
-5v line works as it should .
 
oh well cheered too soon. I connected my Neo Geo MVS today, no sound. Then I plugged in my CPS2 no sound. Great picture but no sound. The PSU I have completely recapped. So I measured +5v -3,11v +5v no 12v and -5 too weak. Mortal Kombat II runs even with sound (why?). I just don't get anything anymore. What can this be, I am so frustrated. If I knew how to install a standard arcade power supply, the old one would be thrown in the trash :(

Please help me guys
If I read this correctly you're getting no 12V? and weak -5V ? CPS2 and MVS need the 12V to power the sound amp.
 
If I read this correctly you're getting no 12V? and weak -5V ? CPS2 and MVS need the 12V to power the sound amp.
That's exactly how it is. In the picture you can see all the caps that I have exchanged. So my biggest Problem is the 12v to run. What else can I do. ?
 

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Sounds like you may have messed up the polarity somewhere, did you doublecheck all the caps?
 

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You said you replaced the caps, so they are very likely all good. I wouldn't bother testing them or redoing the cap kit. I would start looking into resistors or other things that can partially fail in the 12v circuit. how is the 12v generated?
 
You said you replaced the caps, so they are very likely all good. I wouldn't bother testing them or redoing the cap kit. I would start looking into resistors or other things that can partially fail in the 12v circuit. how is the 12v generated?
sorry I have no clue myself all i can say is:

Before the recapping everything except the -5v was working and there was no sound on MK2 and now i can play MK II without a problem even with sound but other things will have no sound.
 
Your 5v and -5v are working.

You have a problem in your 12v circuit. I am saying I don't think it is the caps, but maybe. Can you show pictures of the bottom of the pcb and the capacitor soldering you did. I don't think it would have worked for a while and then failed if you installed the capacitors incorrectly, but we need to just confirm.

I suspect that there was another component in the 12v area that was weak. When you installed the fresh caps that jump in voltage actually probably took it out. This is somewhat common on vintage electronics that you do a cap kit on. This is why it's always good to do burn in tests after a cap kit.

You know where the 12v comes out of the board, and you know where the AC goes into the board. We know 5v is working so power is at least passing the bridge rectifier to become DC. Somewhere between there and the output pin is a problem. it could be a cap, but since you just replaced them all I would start elsewhere. however, new components can fail sometimes too.
 
Here are the pictures you want. I did not change the capacitors myself, an electrician soldered them.
 

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I would bring that back to the electrician, who may be able to diagnose the problem easily, particularly if you're not comfortable working with this stuff. Most power supplies are pretty similar.
 
I don't see any soldering problems that are obvious. So again, I don't think it's the capacitors that are the problem. If there is a schematic or parts list anywhere start comparing your pcb to it. Or just start at the 12v output pin and start working down the trace backwards until you find a problem.

An electrician would certainly be able to check it out, but might charge a lot for that. I would take it back to the guy who did the caps anyways and just see if he will look at it under warranty. Say hey, I don't know why but it was working after you did the job and now it's not, can you take a look and see?
 
I would take it back to the guy who did the caps anyways and just see if he will look at it under warranty. Say hey, I don't know why but it was working after you did the job and now it's not, can you take a look and see?
Yeah this is kinda what I meant, if a rail that was working is no longer working after he serviced it, he should check it out
 
If only it were that simple...

The guy who soldered it is a hobby electrician and I also had to look for him on the internet and send everything by mail. he can solder but otherwise has not much idea of arcade machines.

You know the problem is that in Germany in general hardly noone has a idea of arcades. Our electricians here put a new socket in the wall or hang a lamp. They don't do much more than that.

We don't even have an active arcade forum yet

I don't know anyone in Germany who repairs arcades or sells parts. i need to order all my parts in France, Italy, in the US or Australia.

And when I ask our electricians, they say 110V No idea, Arcades no idea, PSU never heard about ...

So I have no way to get the PSU repaired just around the corner.

@KaPH33n

i cant read schematics but i checked the volts on my mk II and a Neo Geo MVS directly on the jamma pins. nearly the same +5V -3,11V and again +5V
 
I consider myself an expert in re-capping monitor chassis, power supplies, etc.

That said, I still make mistakes every now and then. After double-checking my work I usually find a cold solder joint that I missed or that was created from handling the PCB while re-capping.

I've capped many, many PCBs and mistakes still happen to the best of us. A cap can be put in backwards or more common: A wrong value is installed (4.7, 47, 470 uF I'm talking to you!)

Take a look at the cap kit instructions and double check:
1) Polarity
2) Bi-polar caps are in the right spot and you didn't install a polarized cap instead
3) Values installed are correct (uF matters, voltage can be equal or greater than was used to be in there.)
3) Use a multimeter set to continuity and test the points in the back that share the same traces (the little islands you see between solder points should beep if they are shared). My hunch is there's a broken trace somewhere.
4) If all else fails, remove the solder on each cap using a desoldering gun or a solder pull it (the blue desoldering pump) and check that the pad isn't lifted. Essentially re-doing the cap kit. Trust me you'll find the issue.

Also. Check your diodes with a multimeter. If you have zero +12v that could easily be the culprit too.

Good luck!

Del
 
You know the problem is that in Germany in general hardly noone has a idea of arcades.

So I have no way to get the PSU repaired just around the corner.

@KaPH33n

i cant read schematics but i checked the volts on my mk II and a Neo Geo MVS directly on the jamma pins. nearly the same +5V -3,11V and again +5V
Well, I will just say that the main reason I started to learn about electronics repair was because I wanted to fix my own games. I didn't know anyone who fixed candy cabs 12 years ago. I mostly learned about American games and then transferred that knowledge over to the Japanese games. I would say that you need to just start with the basics, maybe learn about power supplies more generically. Or you will have to find someone that will fix your PSU that you can ship it to.

If you are dead set on replacing the power supply with something else then you need to learn about crimping and connectors. It's not that crazy to create pigtails that connect to the original harness and plug into a modern switcher.
 
Any luck with fixing your power supply? Can you give part numbers for the ICs that are on the heatsinks? I am guessing one of those is the 12v regulator and is blown.
 
Hey, I had brought this on myself. I mistook the pads under the ICs for thermal pads and replaced them with thermal paste. This allowed current to flow and so there were problems ... After the pads were placed under the ICs again, everything ran absolutely without problems. However, I have not found out myself but a very talented user from another forum which I am very very grateful for his efforts!
 
Sounds about right. There are two types of compounds. Conductive and non-conductive. Artic Silver for example is highly conductive and should not be use in these applications.

I learned this in my arcade monitor rebuilding experience and Bob Roberts (old arcade operator who sells parts) confirmed it in his Blog here: https://boulderarcadefactory.com/BobRoberts/hot.html

Glad it all worked out!

Del
 
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