My 2013 27" iMac running 10.12.2 is refusing to sleep on its own. Based on "pmset -g assertions" and activity monitor output, hidd seems to be the culprit. I am using BT Apple keyboard and mouse. Even when I put it to sleep manually, the Thunderbolt Promise Pegasus R4 RAID array doesn't shutdown automatically, the way it used to before. This problem might have started a few months ago even before 10.12.2 update. The only changes, I can recall since it used to sleep without issues are as follows: - Apple replaced the internal hard disk of this iMac under one of the replacement program. - Upgraded to 10.12 I have already reset SMC and deleted all printers. How do I diagnose it further?