Jump to content
Due to a large amount of spamers, accounts will now have to be approved by the Admins so please be patient. ×
  • 0
IGNORED

Astro City PSU Repair


namastepat

Question

Hey guys,

 

One of my Astro City cabs crashed when playing a Neo Geo board, garbage on the screen, the usual kind of low voltage issues. I tested the board in another cabinet and it's working 100%, so I know it's this particular Astro.

 

Did some testing with a multimeter and found that the voltages at the harness and at the PSU itself were jumping all over the shop. Sometimes they would hold a steady 5V and 12V for a couple of minutes and then start to fluctuate wildly, between 2.5V and 4.3V on the 5V line and 8-9V on the 12V line. Holding a multimeter on both the Jamma harness and the plugs at the PSU itself always showed these massive fluctuations. I got @Ryan555 over to confirm my findings with his far better skills and multimeter and he found the same thing. Sometimes it would hold stable, but only for a limited period and then it would begin to fluctuate all over the place.

 

The fluctuation happens on all three voltage lines, 5V, -5V and 12V, so this suggests it is something on the PSU that feeds voltage to all of those lines. We tested the AC power at the PSU and it's rock solid at 115V so we know it has nothing to do with the AC power. It's only the low voltage DC that is fluctuating.

 

So, where would we begin if we wanted to repair this? I have another Astro with an identical PSU in it that I could switch over to the cabinet with the faulty PSU to test that it's not anything in the cabinet wiring (highly doubtful anyway). But I don't want to switch the PSU if I have a chance of damaging it. Both PSUs are labelled as 400-5198 and looked like the one in the attached image.

 

dzQbch.jpg

 

Has anyone repaired one of these PSUs? The steps we have taken thus far are simply measuring the voltages to confirm the voltage drops and then Ryan visually inspecting the decased PSU using a magnifying eyepiece to check for cracked solder joints, bulging caps or anything else dodgy. He did not find anything untoward and we left it there until we can find out more about repairing it, or replacing it.

 

So, if you have any suggestions, fire away. Thanks.

Link to comment
Share on other sites

4 answers to this question

Recommended Posts

  • 0

Buy a replacement.

 

Can be same model or you could use a generic arcade PSU and build some adapter cables. Rig something up for the audio volume and demag switch.

 

Repair wise all I know is to replace the caps. Electronics gurus will yell and scream at this approach, rightly so, but in my experience it's the most common point of failure and an easy task to perform. I've repaired countless PC power supplies this way.

Link to comment
Share on other sites

  • 0

A replacement is always an option, as they are fairly easy to track down on Ebay, but I'd like to have a crack at repairing it first. I have mates who can replace caps very easily and also test them for me, so I might start pulling the large caps on the PSU and do some testing. Might even learn something while I am at it :)

 

I'd rather not use a generic PSU, as I'd like to keep the cab original, it's a pretty nice cab.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...