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Sega Naomi Sun PSU Cap Kit

Omni11

Omni11

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I'd say it would be a good idea to at least open up your working PSU and take a look at the condition of the capacitors.
I had posted a while back about testing an ebay purchased Sun PSU in my Initial D cab. The steering was jerking around by itself with the Sun PSU, but was fine when I used another modified generic PC switching PSU.

When I opened up the Sun psu I could see a few bulging caps, and the board in that area was turning dark from excessive heat.
I've circled the area in the image. There's another image of the blown caps, I couldn't read what value they were but the kit has the proper placement listed.

After replacing all the caps the PSU works great. Just be warned, many of the traces on this board were lifting on me.
Some caps may also be glued to other components on the board, it's pretty soft and easy to cut through to loosen them up.
It was pretty easy to do. Only around 20 caps and the large filter cap.


1.jpg


2.jpg
 
Omni11 said:
I had Ian Kellogg put a cap kit together for my dead Sun psu. It's now up for sale on his website if anyone is interested. Promo code "johnsarcade" gets a 10% discount on that site.
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Thanks for this!

I have two NAOMI PSUs that need new caps but I've been too lazy to put together my own kit.

brentradio said:
Is this recommended for working power supplies?
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Is it recommended that you change the tires on your "working" car? Caps don't last forever they wear out, and you really should replace them before they blow out because if you let it get that bad they'll cause even worse problems.

Inspect your caps, if they look "bloated" then they need to be changed, because eventually they will crack and leak and damage the PCB which at best is a huge pain in the ass to repair or at worse can erode and irreparably damage the board.

Not to mention when caps get old the don't work as well. this is why monitors that need a cap kit get fuzzy or blurry or have image stability issues, PSUs with old caps will have trouble holding a stable voltage and be more susceptible to dips and spikes which can cause your PCBs to lock up or glitch or in severe cases cause damage to your game board (rare but not out of the realm of possibilities).

Audio amps both stand-alone and built into game boards typically have caps that should be checked and replaced as needed (Konami TMNT/X-Men PCBs are a good example of this). Some PCBs have power conditioning caps that should be checked and replaced as well (Chihiro boards are a good example of this).

Most Arcade PSUs just get tossed and replaced whole sale when they start to fail because they cost $15-$20 and a cap kit is usually $8-$10 so why bother. But NAOMI PSUs or other games with expensive or hard to replace PSUs, a cap kit makes a lot of sense.
 
Just tried to order, coupon code doesn't work :( it's only 80c so no big deal, just thought I'd mention it.
 
twistedsymphony said:
Just tried to order, coupon code doesn't work :( it's only 80c so no big deal, just thought I'd mention it.
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Ah, I was surprised it still worked when I used it. I think it was supposed to expire months ago.
Don't forget that filter cap. for some reason he doesn't include it in the cap kit.

Pretty amazing that the caps are all it takes to bring it back to life. Surprised nothing else on the board gets fried since these things were left on almost 24/7.
 
Omni11 said:
Some caps may also be glued to other components on the board, it's pretty soft and easy to cut through to loosen them up.

It was pretty easy to do.
Click to expand...
Is this glue a big white blob? I have one cap that looks like it's fine, just has a big while blob that's stuck to something else.

I blew off all of the dust and man my Sun power supply looks brand new! The seller had about 6 of them on ebay and I picked the one with the highest serial number I could find...glad I did.

:D
 
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brentradio said:
Omni11 said:
Some caps may also be glued to other components on the board, it's pretty soft and easy to cut through to loosen them up.

It was pretty easy to do.
Click to expand...
Is this glue a big white blob? I have one cap that looks like it's fine, just has a big while blob that's stuck to something else.
I blew off all of the dust and man my Sun power supply looks brand new! The seller had about 6 of them on ebay and I picked the one with the highest serial number I could find...glad I did.

:D
Click to expand...
Yeah, it's a white blob of glue. My psu had around 5 or 6 areas glued together, you can see some in the pic. Didn't really seem necessary to me.
 
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