New Astro PSU Voltage Problems

Arcade cabinet hardware and accessories
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Samelak
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New Astro PSU Voltage Problems

Post by Samelak »

First post besides my intro. I was given a mostly stripped New Astro City by another member on the forums (thanks again). After many nights cleaning, sanding, fiberglass and painting (Krylon touch) and gathering the missing parts, I got a complete cab. Unfortunately the PSU I picked up (400-5198-01Y) is having a problem regulating the 5 volts. It continuously fluctuates from 4.2v to 5.1v non-stop. The adjust seems to have no effect. I already recapped the PSU and no difference. I really don't know where to go from there and could use some help. Thanks.

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nem
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Re: New Astro PSU Voltage Problems

Post by nem »

Just to make sure, you have a load connected to the PSU when you're reading the voltage?
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Samelak
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Re: New Astro PSU Voltage Problems

Post by Samelak »

I did not. I'm testing at the JAMMA connector. Do these PSUs act funny without a load? I've tested HAPP PSUs this way before and never had the fluctuating.
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nem
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Re: New Astro PSU Voltage Problems

Post by nem »

Put a load on it and try measuring again.
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RMRM
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Re: New Astro PSU Voltage Problems

Post by RMRM »

You might have a bad potentiometer... If the problems continues, you might want to unsolder it and measure it out of the circuit
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Samelak
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Re: New Astro PSU Voltage Problems

Post by Samelak »

I tried it again with a PCB hooked up, but still the same results. Just fluctuating and I can hear clicking through the speakers. Obviously the PCB is not getting enough voltage consistently to boot properly. I also tested the adjustment pot and it seems to work. I checked for resistance at the min and max settings are there was a significant variance between the two. I can't find anything on this specific model, but I read for a different model that the voltage regulator could be the problem. I have no idea which component that is, so I posted a pick of my PSU below. Any help is appreciated identifying the voltage circuit and components.

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