Mac Troubleshooting: iMac G5 (2004)
Originally release in August 2004 and them re-released in May 2005 with an Ambient Light Sensor (ALS). Main issue facing this version is the iMac G5 logic board failures affecting the video and power component controller. This version of the 20-inch widescreen iMac has a 1.8 Ghz PowerPC 970FX processor, 1GB of RAM (shipped with paired 512MB), 250GB hard drive and a double-layered 8× SuperDrive. Bluetooth needed to be installed at purchase and could not be added later. The iMac G5 series cools itself by using three "ultra-quiet blowers that draw cool air into the system". Heat to dissipate by room temperature air entering through the speaker grill and exits from he slit at the top of the back of the case.
This is where the SMU for the iMac G5 is located. Usually referred to as the PMU (Power Management Unit) or Cuda Switch was re-termed and is located on the top of the Power Macintosh G5 iMac. DO NOT RESET IT IF THE COMPUTER IS ON!!!