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StormyNormy

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Hi all,
I think I need some help troubleshooting my SUN PSU model 400-5397-01 with aNaomi 2 GD setup. After about an hour or so after turning on the cab, the power cuts. Does not happen with a Naomi 1 setup (no GD).
I suspect it to be the PSU rather than the Naomi 2, as the red LED on the PSU is off too. Dont think it is the main transformer, as the CRT is still on (black, no signal obviously).
Fan has been replaced and mounted correctly (22CFM, taking air out); checked heat development of the PSU and it does not "overheat", but did not measure precisely. Don't see anything wrong with the PSU, but I'm no expert. Maybe some of you do.

Thanks for your expertise.

SUN_PSU_2.jpg
 
It needs to be fully recapped, there's a thread here with all the info you need. I've recapped a few and there were leaky / bad caps in all of them, don't put it off as it could easily damage your hardware. The large filter cap is probably fine but replace all the other electrolytic caps with high quality low esr ones some good brands are Philips, Nichicon and Chemicon.
 
Thanks a lot, especially for the link to nem's thread.

Meanwhile, I found this video. Seems there is one particular capacitor that fails a lot.
Unfortunately my multimeter does not have the functionality to check capacitors.

Hope a recap will fix it.
 
The large filter cap is probably fine but replace all the other electrolytic caps with high quality low esr ones some good brands are Philips, Nichicon and Chemicon.
Chose Nichicon caps. Most are obsolete and not all seem to have replacements, did not check the other brands (yet). DigiKey did not provide ESR ratings. The C9 cap I could only get with a diameter of 6.3mm and I stocked some additional C23s (220uF 25V).
Fingers crossed.
 
Finally had the time to desolder all the capacitors today and noticed that the two legs of the component labeled "PC2" next to the cap. C19 had both legs soldered together/bridged on the parts side.

Wondering how that could have happened. Is that supposed to be? What is that component? Does not have any description on it.

Thanks

P.S:
SUN_PSU_PC2.jpg
 
Last edited:
This hobby is constantly throwing curveballs at me. Took my time to place the capacitors, soldered most of them, then realised that at least one trace was damaged:

SUN_PSU_TRACES2.jpg

So my questions are:
-is this an easy fix?
-how can it be done?
-if it is not easy is it safe to just solder the capacitor and continue using the PSU?

Thanks.
 
Ok, it's official, my Universal hates me.
I need to take some time off.
 
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