I have a mid-'11 21.5" iMac that won't sleep correctly. The fan runs non stop (at idle speed) but the display is off so it's only half asleep. What's keeping it awake is _hidd and DisplayWrangler. I'll cut right to the end (after trying everything) and say I replaced the hard drive with a SSD from OWC (with of course the proper heat sensor cable). That fixed it for about a week, but now it's back to fan(s) running constantly.
I guess it's a hardware issue. Does that make sense? I mean, the hard drive is new and the OS is completely rebuilt and up to date (12.6). Oh, I do have RAM from OWC installed years ago but I pulled those sticks out but the problem still persists. All I do is web surf, email and nothing taxing at all like gaming or any photo editing, etc. It's still functional and otherwise flawlessly meets my needs...just irritating.
I guess it's a hardware issue. Does that make sense? I mean, the hard drive is new and the OS is completely rebuilt and up to date (12.6). Oh, I do have RAM from OWC installed years ago but I pulled those sticks out but the problem still persists. All I do is web surf, email and nothing taxing at all like gaming or any photo editing, etc. It's still functional and otherwise flawlessly meets my needs...just irritating.