iMac display turns back on unpredictaby without any keyboard or mouse activity.

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I just switched from my old 2009 iMac to a new 2015 iMac, both running Sierra.

I've set my computer to never go to sleep, and my display to turn off after 10 minutes.

Sometimes the display turns off as ordered, and sometimes it doesn't. More often than not, when it turns on unexpectedly, it doesn't turn off 10 minutes later.

The following are probably meaningless, but I'd rather give you more clues than fewer:

The old computer did not have this problem. It is currently wireless to the router and the printer. It is on, but almost never used.

Frequently, when I'm ready to stop working, I will impatiently turn off the display manually (shift/control/eject) rather than depend on the 10 minute setting, but I have no statistics that relate the unexpected turn-on with the manual turn-off.

Although there is no keyboard or mouse activity, the backup system (CrashPlan) does run in the background every 15 minutes.

The new machine has the mouse, router, and printer all wireless. Keyboard is USB-connected.
The old machine has only the keyboard wireless.


Can anyone explain this peculiarity, or better yet, offer a solution?
 
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CrashPlan Home was killed as of 22 August, 2017, and users are invited to use the Small Business option at $10pm, or $120 a year.

I would uninstall CrashPlan an d use either cloning software, or less preferably, Time Machine, and backup to an external drive.


https://www.lifewire.com/crashplan-review-2617952
 
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MacInWin

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I can't address the sometimes/sometimes not on the turning off, but if you have "Wake for Network access" checked under System Preferences/Power, then when the network queries the machine to see if it's there, or to perform some function, the screen will wake up. I have both "Prevent computer from sleeping automatically when the display is off" and the "Wake..." boxes checked, so what happens is that whenever the system gets something from the network, it wakes up. I have the "Prevent..." checked so that the Mac doesn't drop out of the network when it goes idle.

Bottom line, yes, my system wakes up sometimes in the middle of the night. Usually it's to tell me that a scheduled backup has started, or completed. I don't use Crash Plan, but I do have CCC and TM both scheduled for various tasks between midnight and about 3 am. I've learned to turn the sound down before I leave it for the night, otherwise the "bings" can be disturbing.
 
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Also, some optical mouse are extremely sensitive, and vibrations may cause them to wake the Mac. I turn mine off at night now.
 
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Harry,

I assume that you were just being informative about CrashPlan, and not implying that its activity was causing my display-wakeup problem. If it were, then the wake-up would occur every 15 minutes and, of course, that's not the case. In fact, after I sent in my post last night, the display stayed off all night. I must have scared it. Thanks for the reply, but CrashPlan kept me fully informed, and continues in force for the remainder of my subscription which expires in 2019. They even provided special handling for my situation, which involved installing the Home version for my new iMac just a couple of weeks ago, allowing me to continue under my subscription.

They recommend switching to Carbonite. ****, I switched from Carbonite to go with CrashPlan! I thought Carbonite sucked in one serious respect: Their processing of Outlook would keep its major files in a "pending" state for weeks before getting them covered. Compare that to CrashPlan, which puts newly changed stuff at the top of its to-do list -- it's covered within 15 minutes -- and then catches up on older business after that. It's been years since I left Carbonite, and I'll have to find out if they've improved any since then. Frankly, I hate the idea of leaving CrashPlan, and I'm seriously considering continuing at $120/year. I was afraid it would be more than that, in view of the fact that they will let us continue as a small business with a 75% discount for a year after our subscription expires.

I can't talk about CrashPlan without extolling its merits. I don't have enough adjectives in my vocabulary to do it justice. I'm a (very) old programmer, and I have never before seen such quality, dependability, thoroughness, user-consciousness, documentation (once you get past their user manual), farsightedness, support -- you get the idea. I have yet to come up with a suggestion or concern that they have not already considered, incorporated, and documented with inimitable clarity. Maybe I'm just biased because they're headquartered here in Minneapolis.

Cheers, Bud
 
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Who knows?

Perhaps temporarily disablinmg CrashPlan may resolve the nproblem.
 
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Nope, it aint CrashPlan. I just did a test and closed everything (other than CrashPlan) I happened to have open, including Mail, Firefox, TeamViewer. and maybe one other. I set my phone's timer, and 10 minutes later it dinged and my screen went blank!

Now, let's do a 10-minute individual check on them one at a time, starting with Mail, since that guy is receiving mail at all times in the background. Wanna make any bets?

Actually, now that I think about it, Mail is probably the most likely guilty party that turns the display on unexpectedly!
 
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BudVitoff
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You know how you get that clunking noise from your car until you're about two blocks away from the mechanic, and then everything goes quiet? Well, as you might've guessed, all of the testing worked fine with no symptoms showing up. I thought for sure it would be email.

Which brings up a related question. My iPhone is dealing with the same data as the iMac. When I send an email from my phone to my Mac with both of them wireless to the router, could the Internet actually get involved and have some effect on my problem? Stupid question, I guess, since the server is out on the Internet. It Just shows how much I would rather be working on my easy 20th Century mainframes!

It's just a wait-and-see situation now. Thanks for listening.

Bud
 
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I have a hunch that my iPhone activity might be responsible for the mysterious display turn-on. I have noticed occasionally that my iPhone will do something -- maybe just ring -- and the iMac, about eight feet away, will turn on the display. Maybe they're talking to each other. Who knows what they're saying ...
 

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Make sure that your iPhone is not setup to "receive calls on other devices". If that option is turned on and your Mac is listed as another device you own (with your Apple ID) then it will definitely respond when you receive a call with your iPhone and are on the same network as your Mac.
 
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Well, I didn't expect to get such a quick reaction to a month-old post, but I'm glad it happened.

My iPhone is version 5S, but I have the latest OS installed. I'm having trouble finding ("receive calls on other devices") and the articles mentioned by Jake. I checked the items under Settings > Phone and didn't find anything that seemed to fit the situation. The articles started out being informative, but rapidly got confusing and my iPhone didn't jibe with the instructions. Can either of you give me a step-by-step that will take me to the right control?
 

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Try Settings>Cellular>Calls From Other Devices
 
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I can't find anything like that under Cellular.
 

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What operating system version is on the phone?
 
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MacInWin

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That's curious, Bud. It's definitely there on mine. It's in a section labelled "Verizon" so it may be vendor specific. What is the name of your cellular service? Maybe they don't support the function somehow and so have not put it in as an option.
 
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Life Wireless.

A couple of things:

You say 'It's in a section labelled "Verizon" '. I suspect that you're talking about the status bar at the top. I think that's the cellular service, and practically every screen shows that. Mine shows "Life Wireless" at the top of every screen.

I just checked with my daughter, who has an iPhone7 with Verizon, but she doesn't see "Calls from other devices either".
 
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No, I meant in Settings/Cellular, the resulting screen has a section under a heading of Verizon, and under that heading are four items: Wi-Fi Calling, Calls on Other Devices, Carrier Services and Personal Hotspot. WiFI calling is really great, using WiFi whenever available and the cellular signal is dodgy, by the way. Calls on Other Devices leads to a further screen with an "Allow" slider and once allowed, a list of eligible devices on which calls may be taken.

So, open Settings, go to Cellular and see what's there.
 

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