Chosen Solution
My iMac starts Ok and sign in OK until all the desktop elements are are inplace but once i press the mouse the dreaded rainbow wheel arrears and pointing at any software it become in active (dim light) and the wheel continues going round and round . Safe boot has not resolved the issue. I was told to reset SMU Now the are two ways to do it a0 by taking all cables out wait 15 second put everything back and reboot. This did not resolve the issue b0 to physically to reset SMU that is where I thought this site would be helpful BUT SMU is not on the guide menu Can you possible help ??
Here are a couple of ways. Also when you open it, examines the capacitors (cans) for swelling and or leakage. See LEDs, what is the problem with this model not booting up
