iMac G3 Cooling

simple. you could take the 4 pin molex connector, and hook it up to the lead from the power supply, and use the pass through port to hook to the hard drive. unless the fan uses a 3 pin fan port plug, then your outta luck. I dont think any mac has one of those, thier commonplace on PC boards. howerver, 120mm fans go for next to nothing, and almost all of them come with both plugs (4 pin molex and 3 pin fan) port.

actually, another option, abit not as practical, but it'll alow you to use your current fan. you need 2 pieces of hardware: a molex y-splitter, and a molex->fan connector adapter. the latter actually has 2 fan connectors on it, so if you wanna ada a second one later, that might be better. to hook all that up:

connect the y-splitter to the lead from the power supply
connect one of the molex plugs to the hard drive
connect the other molex connector to the fan connecter adaper
connect the fan to one of the fan pin connectors.

I dunno what strain that'll put on the imac's power supply, or if the SL drive has a standard molex connector. if it does, do either of the two options I mentioned, except substitute the lead for the CD drive. that way, you will reduce the stress from the line for the hard drive, as the optical drive isnt always in use.

hope that helps.

-digital

Yeah, pull power from the HD connector.

But . . . where to put the fan? I puzzled over this idea with our iMac DV, esp. when I bumped it up to 600MHz, but couldn't find an esthetically pleasing spot to put the fan. It really needs to be located at the top of the case blowing air up and out. but it'd take a bit of unappetizing butchery to do. Best case I could come up with involved shrouding the fan and fabbing a duct to blow to the outside.

Alternatively, you could use several small fans located around the edges of the top surface. That'd be much easier to do than trying to fit in a single large fan.

Since the iMac in question seems to run fine so far without a fan, I've done nothing.

dan k

or he could do like what some companies did back with the original compact macs, and make a mac chimney. just take a big piece of PVC pipe and weld it to the side. would look...interesting, too.

or, he could try and find a fan mount from one of the other CRT macs, and fuse into the one he has.

-digital

I've mounted a 40MM fan into the RFI shield, just inside the VGA port door on a slot-loader. I dremeled away just enough metal to form a circle that the fan sucks through, and used some self tapping screws through the holes in the fan and into the RFI sheild. All I wanted to do was encourage upward airflow, before things got hot and started the convection effect. I figured a little encouragement would help things from getting hotter and hotter until the flow started.

I also tapped power from the HDD Molex plug. There ARE Molex to 3-pin adapter cables out there, and some are passthroughs as well.

That cable is exactly what I was posting about. As for the fan, it depends on if you want it to be visible once the iMac is back together and running. Before I did the 40MM fan mod, I had added an 80x80x15MM Zalman fan that took up most of the space where the VGA port door goes. I decided that I liked the smooth back look of the iMac with the door in place and got a smaller fan and redid my mounting.