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G4 psu fan swap


Active Member
Has anyone tried this on there G4

going to give it a shot myself just caus i got 2 spare fans which came out of a thermaltake lan case,

looks straight forward,
not sure if the psu fans are connected with fan connectors or soldered on,
but for the fans am going to use, there will be powered straight from molex for the mean while...

will post pics once done:lesson:
I'd be interested in having a go at doing this. are they 40mm fans? Did they require soldering or was it a 2 pin straight swap?

thanks :)


Active Member
checked it out last night,
and taking apart the PSU is straight forward,
i'd advice getting a nice free area to work on,
i put down a old sheet and then took the PSU out of the G4 as its much easier to work with it that way,

link below of apple's guide on removing the power supply unit-


once you have removed all the screws wiggle the casing apart BUT not fully apart as there is one more screw on the inside which holds the kettle lead socket,
i didn't remove this as it was more then enough space to work with from the front,
the 2 delta fans are connected using a 2 pin fan socket great news so no soldering involved,
remove the fans and then replace with 2 similar fans,
Measurement of fan 60mm x 60mm x 25mm

The Delta fan specs -
Speed - 6800 RPM
Noise - 46.5 dBA
Airflow - 37CFM

Fans i used -
Thermaltake TT-6025A -
Speed - 4550 RPM
Noise - 28 dBA
Airflow - 21CFM

as you can see airflow is much less but from what i have read this should be enough but i have only used these as i had them,
so best get some with slightly better airflow 25/30CFM
i didn't have 2 pin fan conectors for this so i powered them direct from molex...

Pics below


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Active Member
forgot to mention i also tried a simple thing of adding more oil to the delta fans,
i had to use 5 drops of oil on them :eek:
5 on one and 4 on the other before there were fine,
and just this little fix bought the noise down by 5% not much but something...
Thanks for that. I might be tempted to give it a go but would like to find some decent fans first as I'm guessing the quite large drop in airflow between both fans will result in a bit of a temperature jump over long periods?



Active Member
using powerpoint,
fireworkmail and itunes the system idle at 61c

plus i have got a faulty heat sink fan,
also i used a pci fan on the last pci slot you will need to flip it around this way all the hot air which raises gets pushed out...

another fan mod i'll be trying soon,
using 1 or 2 60mm fans am going to insert them right in between the case and heat sink,
these will be right on the side and should keep ur heat sink at 45c all day long,
only thing installing these will mean removing the heat sink,
am 100% one will fit but not sure about 2...
mines been on since 7am and has been running itunes, iphoto, mail, firefox and msn and is now sat at 53oC with both hard drives at 33oC.

i think thats around the normal temp of these computers.


Active Member
am using menu temp to check,
just the cpu temp

for the mean while i have a fan wedge down the size of the heat sink,
as the 120mm tends to stop working,

have you tried CHUD's Nap mode


Active Member
just installed and my temp dropped straight away from idle at 41c now down to 37c,
i downloaded it from the link below,
also install version 3.52

Downloads | aqua-mac.com

my heat sink fan aint working once i receive the one you sent hopefully tomorrow the temp should fall between 35c so be happy with that...


Active Member
another thing which should work fine,

as i had the delta fan on my desk i check the voltage and there can run fine on 5+v
and there sound fine,
so using some thing like a fan mate will be a simple fix increase or decrease the speed as you wish

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