iMac late 2015 not staying asleep

[chanc]

I just got my new 27" 5K iMac and it's awesome. But one issue that I'm seeing is that the Mac is not staying asleep. I usually manually put it to sleep and it does go to sleep. But the next morning, I see that it was woken itself up during the night. I know that also because I get a ton of "disk not ejected properly" messages (because I have external drives connected) when I try to access it the next morning.

In the energy saver preference setting, I have none of the check boxes checked ie. wake on network access, power nap etc..

 

[tjwilliams25]

It sounds like it may be an issue with an external. I would say try disconnecting the one that is force ejecting itself at night and see if that fixes the problem. If it's a WD external, it could just be the sleep settings that it's configured with, as some of them tend to power off automatically which isn't ideal in the Mac environment. WD makes a utility that you can download to change the configuration to stop the Eco Mode from engaging. I was having the same problem a couple of months ago and this fixed it.

 

[chanc]

It sounds like it may be an issue with an external. I would say try disconnecting the one that is force ejecting itself at night and see if that fixes the problem. If it's a WD external, it could just be the sleep settings that it's configured with, as some of them tend to power off automatically which isn't ideal in the Mac environment. WD makes a utility that you can download to change the configuration to stop the Eco Mode from engaging. I was having the same problem a couple of months ago and this fixed it.

Thanks ! It's actually a Seagate, but let me check it out. I actually manually eject the drive before I put the Mac to sleep. But I see that during the night, the Mac has woken itself and re-mounted the drive. And then it's sleep mode kicked in while the external drive is still mounted, leading to the "disk not ejected .." messages. And it does this multiple times as I get a screenful of such messages.

 

[tjwilliams25]

After doing a little research, it looks like this issue could also be happening because of cable placement. USB cables don't have very good shielding on them, so if they're touching power cables they can get interference and cause the USB port to think the cable has been disconnected. Maybe moving some cables around might help the situation? With what you are describing, it sounds like this might be your issue.

 

[chanc]

After doing a little research, it looks like this issue could also be happening because of cable placement. USB cables don't have very good shielding on them, so if they're touching power cables they can get interference and cause the USB port to think the cable has been disconnected. Maybe moving some cables around might help the situation? With what you are describing, it sounds like this might be your issue.

Thanks for taking the time to research this ! I'll definitely check out if cable placement is a cause.