iBook G4 turns on with a really loud fan

I have an iBook G4 (either early 2004 or late 2004, 1.2 GHZ) that doesn't boot up. Instead of booting up, it's fan blows at maximum speed making a lot of noise. There is no display. I can't buy a new logic board. Help would be appreciated, thanks.

iBook

Posted on Aug 4, 2021 8:04 AM

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Posted on Aug 6, 2021 6:14 PM

Usually when the fan runs at high speed it indicates a bad temperature sensor. If a battery is not installed or the battery is bad, then the sensor in the battery may not be registering properly.


See if you can run the Apple Hardware Test. If you don't have the original DVDs which shipped with the laptop, then see if you can get a copy of the AHT from here:

https://github.com/upekkha/AppleHardwareTest


Usually there is an Apple ReadMe file (.pdf) inside the .dmg archive with instructions for creating a bootable external drive (may need to be a Firewire drive for a PPC Mac) or you may need to burn the AHT to a CD.

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Question marked as Top-ranking reply

Aug 6, 2021 6:14 PM in response to MonsterReporter

Usually when the fan runs at high speed it indicates a bad temperature sensor. If a battery is not installed or the battery is bad, then the sensor in the battery may not be registering properly.


See if you can run the Apple Hardware Test. If you don't have the original DVDs which shipped with the laptop, then see if you can get a copy of the AHT from here:

https://github.com/upekkha/AppleHardwareTest


Usually there is an Apple ReadMe file (.pdf) inside the .dmg archive with instructions for creating a bootable external drive (may need to be a Firewire drive for a PPC Mac) or you may need to burn the AHT to a CD.

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iBook G4 turns on with a really loud fan

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