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Sega Astro City -5v problem

Bluechen

Bluechen

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Germany
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
 

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Astro Cities do NOT output -5v
You need a Negatron to add -5v
Hit up @XianXi JNX for his Negatron Atlas adapter. Worth every penny and he ships FAST!
 
Kidkaos said:
Astro Cities do NOT output -5v
You need a Negatron to add -5v
Hit up @XianXi JNX for his Negatron Atlas adapter. Worth every penny and he ships FAST!
Click to expand...
Are you sure about this? I know the NVS-4000 NAC PSUs dont, but iirc many of the Astro City PSUs do. The label on the 400-5198 provided in the pic shows that it does have -5V.
 
Kidkaos said:
Astro Cities do NOT output -5v
You need a Negatron to add -5v
Hit up @XianXi JNX for his Negatron Atlas adapter. Worth every penny and he ships FAST!
Click to expand...
I wrote up this same post and I had to delete it because I looked at the side sticker for the pinout. TIL
 
Bluechen said:
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
Click to expand...
The transistor that handles your -5V is probably hosed. It's a common issue on these power supplies. Your best bet will be to open up the PSU, and use a multimeter in diode test to check it and if it's shorted, then replace it. See the below blog posts for more info.

http://fgaddiction.blogspot.com/2012/05/arcade-psu-debugging.html
https://segamadebaddecisions.wordpress.com/2016/11/22/negative-problems-astro-city-5v-supply-issues/
 
benime said:
The transistor that handles your -5V is probably hosed. It's a common issue on these power supplies. Your best bet will be to open up the PSU, and use a multimeter in diode test to check it and if it's shorted, then replace it. See the below blog posts for more info.

http://fgaddiction.blogspot.com/2012/05/arcade-psu-debugging.html
https://segamadebaddecisions.wordpress.com/2016/11/22/negative-problems-astro-city-5v-supply-issues/
Click to expand...
Came here to link my blogspot post and you already did it! Over 10 years ago now when I wrote that... time really flies.

Bluechen said:
I just ordered a 78L05 transistor and i will replece it. I'll get back to you with the result
Click to expand...
I'm pretty sure it will do the trick. good luck!
 
A complete recapping is ion the way

btw. is there any new / mordern PSU i could use in the future ?
 
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Bluechen said:
A complete recapping is ion the way

btw. is there any new / mordern PSU i could use in the future ?
Click to expand...
You could use a Meanwell PSU with 5V/12V output but you'd lose -5V and would have to use something like a Negatron to get that, if required.

You could also just use a PC power supply.

Both solutions would require you to do some rewiring to work with the existing cabinet wiring.
 
Well, the Aracde runs on 110 V with a voltage converter because we have 230 V in Germany.

Therefore, I am considering the long or short to replace everything so that he runs normally without voltage converter.

I have from my MAK / Supergun a power supply but do not know how I get it in there and everything can connect properly. I would prefer a plug and play solution but I think there is no such thing.
 

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Bluechen said:
Well, the Aracde runs on 110 V with a voltage converter because we have 230 V in Germany.

Therefore, I am considering the long or short to replace everything so that he runs normally without voltage converter.

I have from my MAK / Supergun a power supply but do not know how I get it in there and everything can connect properly. I would prefer a plug and play solution but I think there is no such thing.
Click to expand...
The monitor probably needs 110v no matter what.

unless you want to run 2 power cords I'd stick to using the voltage converter. there's a bunch of threads about what and how you can do to it. Some people mount transformers inside their cabs. Some people buy one big ass one and run multiple cabs off of them. I would personally choose the latter because it maintains the originality.
 
KaPH33n said:
The monitor probably needs 110v no matter what.

unless you want to run 2 power cords I'd stick to using the voltage converter. there's a bunch of threads about what and how you can do to it. Some people mount transformers inside their cabs. Some people buy one big ass one and run multiple cabs off of them. I would personally choose the latter because it maintains the originality.
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Yes, I understand that and actually see it that way. I just think a new power supply would bring me more stability in the long run. I will now wait until the old recapped again and then see if everything works. And if not, I have to think about where I get a new / other power supply. Or I have to send it to KaPH33n so that he repairs it for me. :P:D
 
I would definitely try to repair what you got over replacing it with a modern switcher. but i am a crusty old fart who cares about originality and stockness. most people just want to play their games without worrying about the hardware. the original is fit to the cab and the harness and has -5v built in. Anything else will ultimately feel pretty hack job unless you spend a lot of time repinning connectors and what not.
 
I can really understand you that would be like if I would install a LCD monitor. Has then just nothing more to do with original. But do not worry except new capacitors there is nothing done at the moment
 
yeah new caps and replacing the -5v voltage regulator is a repair, not a complete part replacement.
 
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After I got my PSU back today, I found that everything is running perfectly again. So it was also the µA 78L05 chip with me. I have the whole PSU equipped with new capacitors so that I now hopefully have a while peace. Thanks for all tips. I will have the cabinet ready in 14 days then I share some more pictures.
 
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
 
mortal kombat ii will make the bong on boot up without -5v but it needs it for in game sounds. mvs and cps2 I don't think need -5v so it was probably weak because there's no load on it? not sure.

if mortal kombat ii is making sound in game your power supply is probably fine.

on the mvs there is a volume slider which may be bad? They are also known to lose audio if they need recapping. on cps2 there are issues where it can get corruption to the settings. You can try resetting it by holding vol up or vol down during boot up. If it's a bad supercap then you need to replace that.

Can you try measuring the -5v with mk2 running? Do you have any other cabs to test with or other pcbs?
 
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