Mac Pro PSU to ATX adapter (?)

[pirloui]

Has anyone attempted / heard of any Mac Pro PSU to ATX adapter?
It can't be that exotic (the MP PSU) and soldering to the cables that come with the cases would be easy.
The main difficulty is knowing what pin is what.
I'm not all that knowledgeable with a multimeter, and there are differences between standby power and signal cables and such.

If if was possible it could be really nice, as stock as possible.
Any hints / tips / ideas?

[blackknight]

You had mentioned doing that in a previous thread didn't you? It shouldn't be too difficult, but I don't have a Mac Pro PSU to try it with. It's really just 12V, 5V, 3.3V, GND, and standby 3.3V (I think). There's just multiples of them and you'd have to know what rails they go to so you don't overcurrent them.

Good luck.

[pirloui]

Indeed. Someone mentionned the plans in another thread, and I added I was interested too. Just wanted to create a separate thread about it, in case there would be some interest for it over time.
I live in Honk Kong right now, and there is a shop that have Mac Pro PSUs for 85us$; which is pretty good for a 1000W PSU.
I stripped one of which I use the case only, so the guts might be helpfull for understanding which pin goes to which rail.
(having a look at it)
Actually the strands are grouped on the PCB, and it says 12V1 12V2 and so on, pretty cool.
Maybe possible to do something, even with my feeble electronics skills. (posting picture in a minute)

[pirloui]

[pirloui]

There is up to 12V6, as well as various other things. I will try to start mapping it, posting when there is something.

[blackknight]

That sounds great! Your picture didn't come through though. I figured Apple would have done a pretty good job of labeling. I'd love to have a proper PSU in mine. I'm not sure it would still fit my full ATX motherboard though as it kind of sticks up into the PSU section. I wouldn't mind finding a PSU case though. Good luck with your mapping and let us know if you need any help.

[pirloui]

Thanks, I could need it. I know some basics of electricity, but not that much.
I'll post as I get things done. (not very fast )

[jedric]

This is a great idea.

Moldex connectors should do the trick. Going to to be a lot of crimping but it sure is going to be worth it.

Im in..... Pirloui we need to talk probably will order power supply in HK

[mymainmanbrown]

Hey guys, I just joined aquamac today because I found this post. This was literally the only post I could find on swapping a Mac Pro PSU with an ATX PSU.

Hopefully the work I've done will help you guys, and hopefully you can fill in the holes that I wasn't able to figure out.

So before I could even begin to try to make the swap, I need to get the pinout information for an ATX PSU, which I found here:

en.wikipedia.org/wiki/ATX
pinouts.ru/Power/atx_v2_pinout.shtml

Now, I need to find those pins in the mac. This, however, wasn't quite as easy.

Insanely Mac had a pretty good post about building a Mac Pro, but the guy ended up using a MP PSU www.insanelymac.com/forum/index.php?showtopic=77290 so that doesn't help much.

Originally my thought was to figure out how to turn on the power supply (I figured this out, just plug in the fourth PSU plug and turn the computer on) and test all of the connections with a multimeter, but my lack of knowledge and experience turned me off from that approach.

After more searching, I found this thread, and after seeing the picture that pirloui posted, I knew that if I took the actual PSU apart, I could map most, if not all, of the wires.

So I won't post more pictures of the exposed PSU because they're not as useful as the mapping I did.

Here is the mapping of the blocks and their pinouts:



I also have the diagram for the actual board and its 12V and GND connections, but I don't know how that would help here.

So it seems that the only information I don't have is what the wires on J4 do (technically, J4 is unlabeled, but it's the next in the sequence, so).

Here is the amperage info for each of the rails(?) based on their V number (this is simply the side of the PSU):



Here is what it says (since the picture is a little blurry):

V1 = 13.6A
V2 = 13.6A
V3 = 16.5A
V4 = 12.8A
V5 = 18A
V6 = 11A
VSB = 5A

The PSU is 980W
The 12V amperages add up to 80.5A
The 5V amperage is 5A

This OCZ 1000W has 83A on the 12V rail, so it SHOULD do the trick:
www.newegg.com/Product/Product.aspx?Item=N82E16817341028

However, all of this is just preliminary as I don't know enough about what's going on with J4 and there doesn't seem to be a PWR_OK wire on the Mac Pro PSU.

Does anyone have any other information on making this conversion? It doesn't seem that it has been done yet, but based on this thread and the mapping of the wires, it doesn't seem that it would be incredibly difficult.

As I get more info, I'll post it.

EDIT: the pictures didn't come up, (i DID NOT use the correct syntax), so thanks to the admin for the help!

[aquamac]

Hi, nice post, to get your images to show you need to right click the image you want to show then select: "copy image address" then the syntax to use is the img one finishing with /img, check out looking under modify post. I modified the two images to show OK.

Thanks for the great info too!

[blackknight]

Great work mymainmanbrown and welcome to the forums. I noticed that 5V is not mapped and neither is 3.3V. Have you been able to turn the PSU on at all to verify voltages (I'm guessing not since that would have probably made it easy to check J4)?

[reddrag0n]

I was noticing that too. How can a Mac Pro not use 3.3V and normal 5V for operation? Don't the hard drives and DVD roms require that? Or maybe there is some sort of transformer or capacitor that does that straight from the power input.

[mymainmanbrown]

Hey guys, what I posted was only preliminary testing, and I did see some 5V wires coming out of the power supply's board, but I didn't put a meter on any of the J4 contacts. As for 3.3, I'm not sure as I didn't see anything that said 3.3 and the actual power supply label doesn't mention 3.3, though I find it strange that it wouldn't have this...

I have to use my mac this week so I don't know if I'll be able to do any testing, but once I do, I'll post an update.

[blackknight]

I'm sure there is actually 5V since you said it's labeled on the outer sticker, but 3.3V may be produced on the motherboard from the 5V line. We may have to create a 3.3V line in the adapter.

[mymainmanbrown]

So I got a little antsy and decided to test the PSU anyway and do a little more research. Here is what I have found:

I turned the Mac on and used a voltmeter to test the J4 block. Here is the updated pinout diagram:



I put a W/O for wire out and C/B for circuit board. They don't mean anything to me right now, but maybe they will at some point (see my first post for what this means).

So even though when I took the PSU apart there were no 3.3 rails or solder points in the boards that were labeled, the PSU does in fact convert to 3.3 BEFORE sending to the motherboard. This is great news because it means the ATX power supply can be utilized more (if the 3.3 converting was done on the logic board, the 3.3 wires on the ATX PSU would have to be discarded).

At this point, I'm not all the way there, but I'm making more progress than I thought I'd be able to. There are still a few things I am not sure about.

What do I do with the -12V wire?

What do I do about the PWR_OK wire and the corresponding 3.3V Sense wire? Maybe just solder them together?

There are more 5V and 3.3V wires on the ATX P1 connector (motherboard connector) - what do I do with the extras?

There are fewer 12V wires on the ATX P1 connector - how do I compensate for this?

Do any ground wires need to be matched to specific "hot" wires? I think no, but I'm really not too confident since I only get one shot.

Where can I get female ATX P1 (and others) connectors and male Mac Pro PSU connectors? I want to make an adapter cable rather than cutting wires, especially since there are no tutorials on this.

Here is the ATX PSU I'm thinking about using now:

www.newegg.com/Product/Product.aspx?Item=N82E16817194046

I decided against the OCZ one when I saw that this had 6 12V rails and was better on power consumption (for what it's going to be worth...). I already purchased it. When it gets here, I'm going to take it apart and see if I can identify anything similar to the Mac PSU. Either way, the volts and amps are either the same or adequate, so I don't see a problem yet.

Thank you guys for your support, I'm glad there are a few other people who would like to see something come of this.

As always, let me know if you have any other info or if I am missing anything. Hopefully this won't take too much longer and hopefully I don't ruin a $3.5K piece of equipment!