Hello to everyone,

I'm new to this forum but not to other technical forums and I have a BIG question:

I have a bunch of eMac 700 Digital Modules (Down converter, Logic Board, aluminium drive tray, cables, etc...) from a series of CRT-dead eMacs, but I DON'T have the Analog Modules (power converter) that provides the digital module all the voltages needed for the computer to work.

I've been thinking on using ATX power supplies to make them work but I need advice from all you "Pro" around here, because I'm planning on using these in a "Beowulf-like" computer cluster system in the office, and I have everything prepared, excepting info on power connectors.

I know that the Logic Board's "Blind-Mate" connectors provides all the electric connections, and in macrumors.com forums I saw a post in which someone traced voltages on these "Blind-Mate" connectors, but it gave me no clue to do all the rerouting and rewiring to make the ATX power supplies work, mainly because it had different voltages in each pin wether the emac was on or off.

I see this project like some kind of BIG CHALLENGE, and it would be great to be able to use all the eMac Digital Modules on a Great Performing Processing Center (I'm planning on using it to render video and other calculation-intensive applications).

Any help would be appreciated,

Thanks.

Post edited by: netjosh_granada, at: 2005/01/13 21:44

Post edited by: netjosh_granada, at: 2005/01/13 21:46

Sweet, now if you could just put that cluster in one case, now that would be cool. As for you question-adapting any power supply isn't that hard, especially if you know the pin voltages on you eMac. All you need to do is find the schematics for any PC power supply and wire up a harness for it. As for the eMac connector, I don't know if you can match that. You could just desolder it and put on an atx connector. Good luck....oh, what program will you use your cluster for?

-Maestro

If you can get ahold of an Apple Authorized Repair manual on the eMac, it will list all the voltages for everything so you can ATX-ize the power. Well, I was leaving the repair game when eMac's started to get produced, so I don't have the info. The iMac's did have all the voltage info on the CD that we had, so I would hope that the eMac would in its manual.

Try Google or bribe a tech, possibly find the post that it was mentioned in and work backwards from there. Anyways, if it's on a rumors site, always take it with a grain of salt.

BUT if you do have the voltages and which pins are what, find the pinout on an ATX power supply and work from there. Good luck!

Thanks for the ideas about getting an Apple Authorized Repair Manual. I didn't think this info would be available in this document.

The info about voltages I found in That rumour site came from the same person who achieved overclocking a 2nd generation eMac from 800 Mhz to 1,33 Ghz, so I think it comes from a person who know (more or less) what he does.

But again, thanks.

Refering to the configuration of my proyect, it is as follows (config for each eNode):

- 1st gen eMac, 700 Mhz G4 (FSB100), 256 Mb SDRAM, 10 Gb HD.
- Mac OS X 10.3.7 (for best performance & compatibility in Rendevouz).
- POOCH software (Parallel OperatiOn and Control Heuristic Aplication), from Daugher Research. This software allows to run mutithreaded aplications in different systems trough Rendevouz and 100 Mbps TCP/IP networks.

The HEAD/MASTER node is my "Workstation", configured as follows:

- iBook G4, 800 Mhz G4 (FSB133), 640 Mb DDR SDRAM, 60 Gb HD, Airport Express & Bluetooth.
- Mac OS X 10.3.7 and ALL the programs that can fit in a 60 Gb HD ;-)

One of the upgrades I plan on the nodes is to try tweaking FSB up to 133 and G4s up to 800-933 Mhz.

I'll keep you informed on the project status.

Thanks

you should check the web links section of this site. There are some links to sites with archived repair manuals. Hope you find what you need. Do keep us posted.

I am hoping to do the same thing as netjosh_granada. I have a couple of emac logic boards but don't know the pinouts on the blindmate connector. I've seen the same info about the voltages and am a bit confused about the differing voltages depending on whether the emac is on or off. Somebody must know how to independently power an emac motherboard.

look at http://www.whoopis.com
-Maestro

whitlock wrote:


Sorry to resurrect a dead thread, but I have the iMac service manual and can't seem to find this voltage info you speak of. Is it a separate file? Do you still have it?

I don't have access to it anymore. The voltage info was on a sepperate file, if I remember. I can't remember if it was on the same Apple Service CD, or on a supplimental CD. It's been over a year now, and I cannot remember those details too well, but I do remember seeing them because I had to use a multimeter to test parts of the board all the time.

That is a kick ass project. I would stay away from clocking the bus though. You would need new ram and who knows if thay L Board will handle it without a voltage change. Really I think just up clocking the cpu to 867 could be cool, although you will need to figure out how to cool the cpus better.
-Maestro