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AphoticD

macrumors 68020
Original poster
Feb 17, 2017
2,283
3,466
As discussed in another thread (What chargers work with iBook G3 clamshell?) I have now confirmed it is possible to use a simple headphone jack adapter to step-up the size of the center-pin on the G3 / G4 Power Supply for the more common White iBook G3 / G4 and PowerBook G4 series.

I found a "2.5mm female to 3.5mm male headphone adapter" on ebay for less than AU$3 shipped to my door. The one I got looks like this.

iBookClamshellAdapter - 1.jpeg iBookClamshellAdapter - 2.jpeg

Pay special attention when searching to ensure the female jack is the smaller 2.5mm style, as there are many different adapter configurations available. You'll want something with a narrow girth around the female end so that it can slip under the outer ring of the G3/G4 Power Supply connection.

Initially, I found the adapted 3.5mm connector would push a little too far into the Clamshell iBook power socket, causing a disconnect. So I fashioned a small spacer ring out of a white plastic expanding wall plug to act as a bumber to prevent the connector from pushing in too far and disconnecting.

iBookClamshellAdapter - 3.jpeg iBookClamshellAdapter - 4.jpeg

I've tested on my Clamshell iBook G3 and PowerBook G3 Pismo so far, and will pull out my PDQs, Lombard and PowerBook 1400 to test this mod on those next.

iBookClamshellAdapter - 5.jpeg iBookClamshellAdapter - 6.jpeg

All in all, this is a very cheap, easy, method to using the more commonly available (smaller diameter) adapters on the older (larger diameter) PowerBooks and iBooks.

iBookClamshellAdapter - 7.jpeg iBookClamshellAdapter - 8.jpeg
In terms of safety, I can confirm there are no sparks/shorts and it is safe to hold - I am testing here with a 65w adapter suited to the PowerBook G4 15" (Aluminum). As the outer ring is no longer involved in the connection, I would assume there is no earthing, but this doesn't appear to cause any issues. I have been using a hacked adapter which looks a little like this (no outer ring), but it is soldered together, for several years with no negative impact on my iBooks or PowerBooks.

iBookClamshellAdapter - 9.jpeg iBookClamshellAdapter - 10.jpeg

I hope this helps anyone who wants to power an older portable Mac, but only has access to the smaller style connector and doesn't want to do an irreversible mod to their Power Supply.
 

TheShortTimer

macrumors 68040
Mar 27, 2017
3,249
5,638
London, UK
Thanks for sharing this invaluable information with the community @AphoticD. :)

It probably needs to be a sticky because I forgot about this little trick and missed out on a relatively cheap Clamshell as it was "untested" and lacked a power adapter and I didn't fancy having to track one down in addition to the gamble on a likely dud.
 
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AphoticD

macrumors 68020
Original poster
Feb 17, 2017
2,283
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I did this with my old Clamshell too - though I didn't use an adaptor but replaced the shrouded plug with an audio jack (which means cutting wires!)

Yes, I had done the same, but was pleased to discover this little nugget. I put the 2.5mm to 3.5mm adapter in my kit with the Magsafe 1 > 2 adapters for easy access.
 

Nekomichi

macrumors 6502
Sep 20, 2016
299
459
Theoretically, this should also work the other way around, right? I have a PowerBook G4 with the 2.5mm charging port and an iBook charger with a 3.5mm pin. Have an adaptor on the way but thought I'd just check here.
 

Nekomichi

macrumors 6502
Sep 20, 2016
299
459
Theoretically, this should also work the other way around, right? I have a PowerBook G4 with the 2.5mm charging port and an iBook charger with a 3.5mm pin. Have an adaptor on the way but thought I'd just check here.
Update: It doesn't work directly and requires some modification. After connecting the adaptor, the sleeve of the 2.5mm connector was correctly the 24V pin, but for some reason ground was on the tip and not the ring. I had to re-wire the socket to switch the tip and ring around. After that, it worked on the PowerBook.
 
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