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Omer Mushahwar
Omer Mushahwar, Computer Hardware Engineer
Category: Mac
Satisfied Customers: 309
Experience:  I work with Mac Computers and Servers on a daily basis
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My Mac G4 powers on but the chime doesnt happen and the fan

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My Mac G4 powers on but the chime doesn't happen and the fan begins to run very hard. Is there a way to get it to turn on?

Omer Mushahwar :

Hi and welcome to Just

9 times out of 10 this issue is related to a hardware issue usually relating to the Logic board but there are a few things we can try to make it work just to rule them out

Do you have the OS disc for your computer? One thing you can try is to boot the computer up with the disk in the drive and hold down C this should have your mac boot to your disk

Omer Mushahwar :

If the OS disk wont boot the next thing we can try is resetting the CUA/PMU The steps from apple can be found here


  1. If the computer is on, turn it off.

  2. Disconnect ALL cables from the computer, including peripherals and power.

  3. If possible, move the computer to a place where you are not standing on carpet.

  4. Open the case and ground yourself by touching part of the metal frame inside the computer.

  5. Press the Cuda or PMU button ONCE. Do not press the button more than once before starting the computer up again.

  6. Wait 10 seconds, then reconnect the cables you removed in step 2 and turn the computer on.

  7. If the computer still does not respond after resetting the PMU, the computer may require service from an Apple Authorized Service Provider.

    At the bottom of the webpage I linked they show you exactly where the PMU button can be located based on your type of Mac G4 you will want to expand the For Power Mac G4 under the heading to find PMU/CUDA

Omer Mushahwar :

Let me know if either of the steps provided here help with the issue
Also while you have you computer open for the PMU reset you may want to look at the memory and video card to make sure nothing has come loose.

Omer Mushahwar and 2 other Mac Specialists are ready to help you

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