Give me an EMC #. It's located at the bottom of the door. What is your current RAM configuration (this is critical) how much and in what slots? Have you changed the battery? Do you have a volt meter? We may be testing the power supply output later without tearing into anything. You don't want to replace the power supply because you don't have the CPU synchronizing software that is on the Apple Service Disk (ASD) that only authorized service providers have. I've been trying unsuccessfully to get one for two years. Without this the fans run wild when the power supply is replaced. I own this machine and just put a new video card in it today. So I'm familiar with it.
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UPDATE
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The fan syncing software is on the original system installation disks.
Give me an EMC #. It's located at the bottom of the door. What is your current RAM configuration (this is critical) how much and in what slots? Have you changed the battery? Do you have a volt meter? We may be testing the power supply output later without tearing into anything. You don't want to replace the power supply because you don't have the CPU synchronizing software that is on the Apple Service Disk (ASD) that only authorized service providers have. I've been trying unsuccessfully to get one for two years. Without this the fans run wild when the power supply is replaced. I own this machine and just put a new video card in it today. So I'm familiar with it.