Hi, So my iMac is failing to shut down properly when I hit the apple shut down command. What happens is the screen goes dark I get the spinning gear wheel and it spins perpetually. I can feel what I suspect is the hard drive/fan (it's a 2TB fusion) doing something but ultimately after 10+ mins I decide to power off. The computer is 4 days old in my possession (bought as a returb from the apple store). I have put 32gb of OWC ram in it. Here is what I have done to solve: 1. Reset SMC and NVRAM. 2. Cleared cache (using disk aid app purchased from App Store). One thing I would say is that when I turn on the computer and then try to shut down straight away the computer does so without problem. I suspect some process is initiating and then ultimately frustrating attempts to shut the computer down after 30 mins or so of typical use (iTunes, mail, safari etc). I am careful to have all apps closed before attempting to shut down so I ensure no processes are running but I can't see or understand what is happening. Are there terminal scripts I can see to understand what is going on? Hope some of you guys can help.