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LOLZpersonok
Oct 15, 2012, 12:08 AM
Is it located by the CRT or underneath the computer? I don't know because I didn't find any heatsinks.



AlphaDogg
Oct 15, 2012, 12:12 AM
I don't know because I didn't find any heatsinks.

There is one, but it's tiny; about 1cm thick.

It's under the CRT, about 6 inches behind the disc drive.

Intell
Oct 15, 2012, 12:30 AM
I'm assuming you have a slot loading G3 iMac, because the tray loading ones have a heat sink. If the iMac is upside down with the white bottom cover off, the CPU is located on the CRT side of the logicboard. It uses the EMI shield between the two halves as a heat sink with a heat dissipation pad between them. It is roughly located in the middle of the logicboard. You can tell where it is because you'll see a large square patter of traces and solder points on the logicboard.

AlphaDogg
Oct 15, 2012, 12:31 AM
I'm assuming you have a slot loading G3 iMac, because the tray loading ones have a heat sink. If the iMac is upside down with the white bottom cover off, the CPU is located on the CRT side of the logicboard. It uses the EMI shield between the two halves as a heat sink with a heat dissipation pad between them. It is roughly located in the middle of the logicboard. You can tell where it is because you'll see a large square patter of traces and solder points on the logicboard.

Oops I forgot those slot loading ones existed..

orestes1984
Oct 15, 2012, 06:12 AM
On a daughter card on the logic board that pulls out from the tray under the CRT.

Intell
Oct 15, 2012, 10:11 AM
On a daughter card on the logic board that pulls out from the tray under the CRT.

Slot loading CRT iMacs don't have a daughter card. The CPU is soldered directly to the logicboard.

orestes1984
Oct 15, 2012, 10:18 AM
Slot loading CRT iMacs don't have a daughter card. The CPU is soldered directly to the logicboard.

Ahh cool, I've never had to completely tear down a slot loader, only along time ago did I open up the door of one to install some RAM. Never owned a slot loader, only the Rev A Bondi Blue one with the IR port and mezanine slot.

MAC MAN JW
Oct 15, 2012, 12:41 PM
I had a spare logic board off a 500MHz slot loading iMac g3 so i pulled it out to take a pic.:) The CPU is the silver chip in the picture.

369630

369631

LOLZpersonok
Oct 15, 2012, 08:39 PM
There is one, but it's tiny; about 1cm thick.

It's under the CRT, about 6 inches behind the disc drive.

Ah yes, I have an idea now. I guess I didn't recall it until I saw your post. I think the small heatsink I saw may be it. Thanks, I was really wondering about it.

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I had a spare logic board off a 500MHz slot loading iMac g3 so i pulled it out to take a pic.:) The CPU is the silver chip in the picture.

369630

369631

The IBM chip? Did IBM manufacture the PowerPC CPU's in the older Macs?

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Slot loading CRT iMacs don't have a daughter card. The CPU is soldered directly to the logicboard.

I already know that. It's unfortunate that they didn't include it on a Daughtercard, the CPU could have been upgradeable.

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I'm assuming you have a slot loading G3 iMac, because the tray loading ones have a heat sink. If the iMac is upside down with the white bottom cover off, the CPU is located on the CRT side of the logicboard. It uses the EMI shield between the two halves as a heat sink with a heat dissipation pad between them. It is roughly located in the middle of the logicboard. You can tell where it is because you'll see a large square patter of traces and solder points on the logicboard.

Yeah, it's the slot-loading 350MHz iMac G3. I think I remember seeing it, but before I wasn't sure what it was because it was so small.

AlphaDogg
Oct 15, 2012, 09:27 PM
Did IBM manufacture the PowerPC CPU's in the older Macs?

PowerPC processors were indeed manufactured by IBM.

orestes1984
Oct 15, 2012, 09:42 PM
IBM and Motorola

LOLZpersonok
Oct 15, 2012, 09:52 PM
PowerPC processors were indeed manufactured by IBM.

Oh okay, thanks.

Intell
Oct 15, 2012, 10:16 PM
PowerPC processors were indeed manufactured by IBM.

IBM and Motorola

Pre-G3, G3, and G5 were IBM. G4's were Motorola. IBM, Apple, and Motorola all had a part in making all four versions.