From the knowledgebase re fan issue: Resetting the SMU can resolve some computer issues such as not starting up, not displaying video, sleep issues, fan noise issues, and so on. If your computer still exhibits these types of issues even after you've restarted the computer, try resetting the SMU.
To reset the SMU on a Power Mac G5 (Late 2004) computer, simply do the following: Turn off the computer by selecting Shut Down from the Apple menu or by holding the power button until the computer turns off. Remove the power cord from the computer. Wait 15 seconds. Plug in the power cord. Turn on the computer. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2102 bytes Desc: not available Url : http://www.math.louisville.edu/pipermail/macgroup/attachments/20051102/22e8b021/attachment.bin
