Macintosh SE/30 replacement PSU question

[Mikeosoft]

Hi I am in process of restoring my Macintosh SE/30 and thanks to JDW’s awesome video I am going to replace the stock unit I have with a seasonic. The only issue I’m worried about is that I couldn’t find the same model for anywhere near the price range it was once at, but I did find and purchase a similar seasonic model.


“Seasonic SS-250SU 80 Plus 250w Server Power Supply”

From the limited looking I did I think this unit will work, I was just wondering if anyone here can chime in with some insight if possible.

Also while on the subject, I noticed when searching for a capacitor list to replace the ones in my stock psu that my unit isn’t really listed anywhere. I’ve included pictures here of the apple psu part #: 631 - 5105 - A it’s apple branded and says manufactured in Singapore.

 

[AndyDiags]

It’s the Hitachi power supply.
Notice the text “S’PORE PTE LT” match.

Macintosh SE/30 Power Supply Cap Kit: Apple 820-0385-A / Hitachi

<p>Full cap kit for the Apple / Hitachi 820-0385-A / 631-5105-A power supply found in some Macintosh SE/30 computers, attached to the analog board.</p> <p><strong>Notes about this kit:</strong></p> <p>Original 620uF main filter cap will be replaced

console5.com

Seems to have went Aztec -> Hitachi -> Sony from what I’ve seen with Aztec used in ‘89, Hitachi in ‘90, and Sony ‘91, roughly.

 

[Mikeosoft]

Awesome thank you, I think I will hold off recapping this powersupply for now and just remove the caps, clean it with vinegar, and put it into storage. I am going to Frankenbuild the best se/30 from two machines I have. One of them has the Aztec psu that is still operational but I’m going to investigate that one once I get the seasonic psu. The analog board from one of these machines has a much better transformer on it (less white build up) and the monitor looks to have less hours on it. However the motherboard for the second one has had a horrible battery bomb in the past that I think makes it not worthy of restoring. Hopefully one day I can move the parts onto a new pcb.

 

[Kay K.M.Mods]

Not long ago, I made a SE/ 0 PSU using a Flex ATX power supply. It has -12V so I didn't have any trouble. LED monitors for each bolt is attached just in case. Please note that the + 5V voltage may be slightly lower depending on the PSU used.

 

[Mikeosoft]

Hey all,

Just wanted to give an update.

The thread on that other forum from 2018 contains photos that are no longer linked or the url's are down, so I had to cross reference the pinouts from here, thanks to Eric, JDW, and everyone else involved:

Eric Bylenga :: Welcome

Here's some pics of the power supply installed.

I used some brass standoffs from my MiSTer build parts, I drilled out two small holes in the bottom of the original PSU case to mount it inside, left off the seasonic's top cover plate but I reapplied the heatsink sheet for some reason I'm not too sure since it doesn't actually mate up flush to the top of the original case. I soldered the green PSU on wire directly to ground terminal on the case. I also cut away and heatshrinked all the extra wiring I didn't need from the seasonic, since this psu I bought doesn't have the modular removable connector. I was originally going to desolder the wires from the seasonic directly, but when I got in there I noticed there was solder over bundled large gauge crimping, and tbh I didn't want to dig out my dad's old weller solder gun from the 1960's...

Anyways, I just finished recapping the analog board for this SE/30 I will swap this analog board along with this seasonic PSU into my SE/30 that works to test and report back.

Thanks everyone.

 

[EdRetroTech]

Hey all,

Just wanted to give an update.

The thread on that other forum from 2018 contains photos that are no longer linked or the url's are down, so I had to cross reference the pinouts from here, thanks to Eric, JDW, and everyone else involved:

Eric Bylenga :: Welcome

View attachment 3246


Here's some pics of the power supply installed.

I used some brass standoffs from my MiSTer build parts, I drilled out two small holes in the bottom of the original PSU case to mount it inside, left off the seasonic's top cover plate but I reapplied the heatsink sheet for some reason I'm not too sure since it doesn't actually mate up flush to the top of the original case. I soldered the green PSU on wire directly to ground terminal on the case. I also cut away and heatshrinked all the extra wiring I didn't need from the seasonic, since this psu I bought doesn't have the modular removable connector. I was originally going to desolder the wires from the seasonic directly, but when I got in there I noticed there was solder over bundled large gauge crimping, and tbh I didn't want to dig out my dad's old weller solder gun from the 1960's...

Anyways, I just finished recapping the analog board for this SE/30 I will swap this analog board along with this seasonic PSU into my SE/30 that works to test and report back.

Thanks everyone.

Hi Mikesoft!

I'm about to endeavour into the same PSU swapping for my SE/30. Did you manage to complete the swap with the Seasonic PSU? Did it work well?

Thank you for you detailed post.

 

[fred1212]

I've gone with this, very pleased. https://github.com/dekuNukem/PicoRC/blob/master/mac_se_se30.md#pre-flight-checks