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The Godfather · Apr 21, 2002, 11:46 PM

I am a cheap geek and wanted a sub $300 OSX machine for development. So, I finally caved in to buying a Mac mobo. It is a 400 MHz iMac logic board with firewire (eventually I'll buy a used iPod).

I know that vmarks experience is with 1st gen iMac boards, and that he'd like me to buy his converter, but I wanted firewire and AGP graphics.

Anyway, here's a closer look (from the top).

I still haven't got it in the mail but it will soon. Anyone has a clue on what power supply it will take to run it? Will vmarks converter do the job?

The Godfather · Apr 22, 2002, 01:24 AM

This is a pic of the front and back of a 350MHz iMac mobo. Does it look like the same power connector as a 1st gen iMac?

[ 04-22-2002: Message edited by: The Godfather ]

vmarks · Apr 26, 2002, 09:21 PM

Sorry to be late to respond.

Congratulations on getting a nice motherboard!

I'm working on the adapter for this motherboard, but haven't got it ready yet. I'll be sure to announce in the modification forums when I do have it ready, but until then, no, the connectors are not the same.

The Godfather · Apr 28, 2002, 12:47 PM

Originally posted by vmarks:
Sorry to be late to respond.

Congratulations on getting a nice motherboard!

I'm working on the adapter for this motherboard, but haven't got it ready yet. I'll be sure to announce in the modification forums when I do have it ready, but until then, no, the connectors are not the same.

Can I have a beta or alpha design of this new adapter? I have read through all the sites that explain how to feed a Mac tower with an ATX supply, but I am not sure if it will work with the 2nd gen iMac.

I am very tempted to buy and return an iMac just to test the power supply.

seanyepez · Apr 28, 2002, 06:01 PM

Originally posted by The Godfather:
I am very tempted to buy and return an iMac just to test the power supply.

I hate people who do things like that.

The Godfather · Apr 28, 2002, 08:50 PM

Originally posted by seanyepez:


I hate people who do things like that.

Well, you'll just have to hate me when I do that.

It's all for the love of science

vmarks · Apr 29, 2002, 11:37 PM

Hi Godfather-

I keep missing you in IRC.

I don't have that adapter worked out just yet, but we can talk about getting you one of the test versions when I have it all sorted out.

If you find an iMac to measure power supply voltages on, great. I'm not sure I can endorse buying and returning one as the right way to go about this.

There's no reason to trust that the connections should be the same as any on a powermac, and the circuits used to adapt a powermac to ATX don't work the same as the earlier iMacs, so I don't trust that the newer iMac that you have is the same either.

MacManMikeOSX · May 15, 2002, 01:26 PM

Dr Vmarks Could you also email me at Mdthompso89@mac.com when you get it worked as I have a iMac 2 gen. motherboard and would like to use it.

Nicholas Savage · May 17, 2002, 01:55 PM

converting a slot-load imac mobo isn't going to be all that easy; your going to need the down converter board (powersupply) which connects to the black molex on the side of the motherboard. . .and the pinouts for the socket that connects to the video board (for power in) . . .royal pain in terms of wiring to get that all working. routing ports and getting the video working shouldn't be that much trouble. . . .it's just the power issues.

Langdon · May 19, 2002, 08:49 PM

I have a Grape iMac DV that has a quickly dying monitor. Just looking at the motherboard diagram it doesn't look very hard to mount it in another box if I don't go rearranging the ports or playing with the powersupply. In reading all this thread I am still not sure what benefit there is to using an ATX powersupply. Why not use the iMac powersupply in the ATX case? Even though its small it should power a hard drive and a standard Apple compatible DVD drive, right?

If I were to take on this project can I just gut an ATX box or any box and mount the iMac board in there? Will there be heat issues? What other mounting problems have you all encountered.

Thanks

[ 05-20-2002: Message edited by: Langdon ]

Langdon · May 20, 2002, 08:21 AM

One more thing. This may be a dumb question but do i need to also pull that second portion of the iMac that lies directly above the motherboard: On which the CRT lies that has the vertical heatsink on the right side?

The Godfather · May 20, 2002, 08:33 PM

I think that white circuit board above the motherboard is the analog circuit that drives the CRT. If you use an external CRT, it will come with that circuitry inside.

vmarks · May 21, 2002, 09:27 PM

The powerboard and analog video board are integrated into that one cream colored board that mounts above the motherboard below the crt.

As for nay-sayers who ask why:

The analog video board fails, and takes the power supply with it. Using an ATX supply is one way to keep the machine going, and the ATX supply is an affordable reliable part that can be sourced from anywhere.

Sure, if you have a working supply and just want to place it in a small case, fine- do that. But if you have a dead supply, the ATX solution makes good sense. Sure, it's mildly difficult to figure out, but once it's been figured out, it can be replicated easily. The work only has to be done once.

Langdon · May 21, 2002, 09:48 PM

Hey Vmarks,
I sent you an email.