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AphoticD

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Feb 17, 2017
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I have a low cost opportunity to upgrade a 1st gen PB12” G4 867mhz with a logic board from the last gen 1.5ghz model. The boards appear to have the same layout and connections. The only real difference after studying the ifixit teardowns is the 867 had a somewhat skimpier looking heatsink.

Does anybody know if this is doable or has anybody succeeded in doing this?
 
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weckart

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Nov 7, 2004
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From what I can remember, the 867MHz was an one-off in terms of layout and internals and prone to overheating. Good luck.
 
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AphoticD

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Feb 17, 2017
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From what I can remember, the 867MHz was an one-off in terms of layout and internals and prone to overheating. Good luck.

This is my impression also. I wonder how much of this is due to the hot running 7455 vs the lower voltage 7447 used in the 1Ghz and the 7447A in the 1.33 and 1.5ghz models. I might have to take a gamble on it just to get the two boards in hand to see if everything lines up or not.
 
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1042686

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Sep 3, 2016
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Or you could just buy one of each machine, do the swap & if it doesn’t work who cares, you have two cool macs.

Makes total sense to me. :D
 
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AphoticD

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Feb 17, 2017
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Or you could just buy one of each machine, do the swap & if it doesn’t work who cares, you have two cool macs.

Makes total sense to me. :D

Well the 867 is (mostly) complete and in good physical condition except it is apparently refusing to boot. The HDD has been removed by the seller so it could just need a new HDD or it could be something more fatal like a corroded PMU capacitor and/or a crashed PMU. The 1.5ghz naked logic board on the other hand is $5 untested, so it’s all a gamble anyway.

I recently took a punt on a dead iBook G3 700mhz (16MB VRAM Opaque), which wasn’t booting. My first attempt was to apply pressure to the GPU which got it booting. I stripped it down, renewed pads and added an extra pad to the GPU between the EMI shield and the plastic bottom casing. While I had it out I noticed the PMU capacitor had leaked and there were very mild marks of oxidized battery goop around the PMU circuitry. I cleaned it up and put it together and it worked perfectly for a few days. Then no response to power. I tore it down and replaced the capacitor (I had some spares from my blueberry iBook fixes). Despite all my efforts I think the PMU is fubar. .. so I found a matching replacement board for $20 coming in from the UK.

@DearthnVader will I? This is the kind of info I’m looking for. Do you know if they do have different display connections?
 

LightBulbFun

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Nov 17, 2013
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when ya do get the 867Mhz machine if it does work

can you test Mac OS 9.2.2 on it? im really curious if the GeForce4 420 Go work in OS 9.2.2 like the 440 Go in the 17 inch PB of the same age.

and if you do end up taking it apart some CPU shots would be very much appreciated :) I have not seen any high rez pictures of the CPU in a 867Mhz 12 inch PowerBook.

as for swapping boards around I know the 1.5Ghz 12 inch PB uses a USB based Track Pad and Keyboard where as the 867Mhz machine uses an ADB one so theres a bit of a big road block right there im afraid :/
 
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AphoticD

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when ya do get the 867Mhz machine if it does work

can you test Mac OS 9.2.2 on it? im really curious if the GeForce4 420 Go work in OS 9.2.2 like the 440 Go in the 17 inch PB of the same age.

and if you do end up taking it apart some CPU shots would be very much appreciated :) I have not seen any high rez pictures of the CPU in a 867Mhz 12 inch PowerBook.

as for swapping boards around I know the 1.5Ghz 12 inch PB uses a USB based Track Pad and Keyboard where as the 867Mhz machine uses an ADB one so theres a bit of a big road block right there im afraid :/

Ahhh.. that will certainly be a showstopper. I am interested in seeing how the original series handles anyway. I also noticed the Openmark wiki needs a 420 Go result :)

I read that the OS9Lives folks had gotten the 867 to successfully run 9.2.2. I’m not sure about accelerated graphics though.

I think I will pickup the $5 board anyway. My current PB 12” 1.5 has a blown Firewire controller, so I’ll put that job on the list of fixes.
 
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DearthnVader

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Dec 17, 2015
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Red Springs, NC
Well the 867 is (mostly) complete and in good physical condition except it is apparently refusing to boot. The HDD has been removed by the seller so it could just need a new HDD or it could be something more fatal like a corroded PMU capacitor and/or a crashed PMU. The 1.5ghz naked logic board on the other hand is $5 untested, so it’s all a gamble anyway.

I recently took a punt on a dead iBook G3 700mhz (16MB VRAM Opaque), which wasn’t booting. My first attempt was to apply pressure to the GPU which got it booting. I stripped it down, renewed pads and added an extra pad to the GPU between the EMI shield and the plastic bottom casing. While I had it out I noticed the PMU capacitor had leaked and there were very mild marks of oxidized battery goop around the PMU circuitry. I cleaned it up and put it together and it worked perfectly for a few days. Then no response to power. I tore it down and replaced the capacitor (I had some spares from my blueberry iBook fixes). Despite all my efforts I think the PMU is fubar. .. so I found a matching replacement board for $20 coming in from the UK.

@DearthnVader will I? This is the kind of info I’m looking for. Do you know if they do have different display connections?
Almost certainly.
 
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