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kryptticAZ

macrumors 6502a
Original poster
Feb 26, 2007
818
1,104
Phoenix, AZ
I have a 34" LG display hooked up to my MBP via the TB3-->TB2 adapter. When I put the computer to sleep, the monitor goes to a gray screen and says "no signal, entering power save mode shortly" and then the display goes black.

However, the screen goes back to that gray screen several times an hour with the same message about entering power save mode shortly. It's like something is waking it up for a split second. I have all display options (Power Nap, Wake for Wi-Fi network access) turned off in system preferences, so I don't know what else to try short of physically powering off the monitor when I'm done using it.

Any suggestions?
 

Uhu

macrumors regular
Feb 4, 2010
128
17
I thought I was the only one. My two LG monitors always wake up from time to time just to fall asleep again. That’s really annoying because they do a beep every time they wake up
 

kryptticAZ

macrumors 6502a
Original poster
Feb 26, 2007
818
1,104
Phoenix, AZ
I thought I was the only one. My two LG monitors always wake up from time to time just to fall asleep again. That’s really annoying because they do a beep every time they wake up

What do you end up doing? Just ignoring it, or unplugging when you're away from the computer for awhile? I hate to turn off the monitor or unplug, because the USB-C cord also charges my computer.

I've seen many other posts about this, but can't seem to dig them up right now.
 

AdamA9

macrumors 65816
Feb 2, 2010
1,232
355
Do you have the monitor set as the primary display? It could be notifications waking it up.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
28,601
12,717
To me, this would indicate a problem with the -Mac-, and NOT "with the display".

Something -- a background process, network access, something -- is causing the Mac to wake up while sleeping.

When it does, it wakes up the display along with it.

Find out why the Mac keeps waking up, and I'll bet it solves the display wakeup problems, too.

Fishrrman's quick, easy way to prevent the display from waking:
Reach over to the power button, and shut the display OFF...! ;)
 

kryptticAZ

macrumors 6502a
Original poster
Feb 26, 2007
818
1,104
Phoenix, AZ
Turn the display off also cuts off power for charging the MBP. So I'd rather not do that.

I have all notifications turned off and have set Do Not Disturb set while the display is sleeping as well. I agree that this is not a problem with the display, as this happens both with my LG and Dell displays. I've read other reports from people that have the same issue, but apparently only when connected via Thunderbolt or USB-C.

Here's one of the reviews on Amazon for the Dell:

"When connected to a MacBook Pro 2018 or 2016 via the Thunderbolt 3 USB-C port, the display does not stay off when the system is in sleep mode. It awakens once a minute to complain there is no signal and then turns off. This happens when only the Dell U3818DW is hooked up but if there are other devices hooked up on another Thunderbolt 3 port of the MBP, they are awakened by the Dell U3818DW (aka they are fine without the Dell). Similarly, with only the Dell U3818DW connected, the MBP 2018 reboots 15 seconds after being shutdown. MBP 2016 shutdown ok.

Sleep and shutdown work fine if connected via the Display Port but the downside to that for MacBook Pro owners is that you:
1) Require an adapter or dock that provides a display port interface
2) Require another USB-C cable connected to the MacBook Pro for charging
3) Require a 3rd cable between MacBook Pro and monitor to make the monitor's USB ports"
 

Uhu

macrumors regular
Feb 4, 2010
128
17
I just realized something interesting. My displays do a beep when they get woken from suspension, so it was easy to realize:
I got a Whatsapp on my phone and in the same moment my macbook woke up (I use Franz messenger app). I think there are some issues with the power management .
PowerNap is disabled
 

spacegoose

macrumors newbie
Jun 11, 2011
6
0
I have the same problem with my MacBook Pro 2018 and a Dell U3818DW. It is connected via USB-C and when I put the Mac to sleep, the monitor goes into sleep mode as well. After a few minutes, it starts searching for connected devices again and the MacBook Pro emits the "charging" sound. After a few seconds the display and the laptop go to sleep again... and this happens over and over again. Somehow I have the feeling that the MacBook Pro sends something over USB-C so that the Monitor awakes from sleep mode. If this initial trigger could be somehow disabled, the problem probably would be solved. Any thoughts?
 

Rcarlino3

macrumors newbie
Nov 7, 2018
1
0
Same issue! Just got my 2018 i9 MBP and I have it going to the Dell U3818DW via USB-C. When i shut the MBP down, the monitor goes into sleep mode, wakes up to look for a signal, thus causing the MBP to wake up and start again. I think I may have solved the issue by making the MBP the "Primary" monitor and the Dell is the "Secondary" monitor. Last night it did not wake up until my husband turned on the monitor this morning to use the iMac we have hooked up to the monitor. because the last input I had on was the USB-C input, it woke the MBP up. I assume if i changed the input to the iMac input before I turned it off, then my MBP would have stayed off.

I think this solves my workflow issue but will do some more testing to confirm.
 

bonovski

macrumors newbie
Jan 24, 2019
3
0
2016 13” MBP with two dell 2718Q here.
Only one of these two keeps doing this and it’s really annoying.

When in clampshell mode the “primary” monitor will more often than not get into this loop, I have to switch it off with the button and when I switch the monitor back on it stays sleeping. IMHO because macos doesn’t see it as the primary monitor anymore.

It’s definitely a macos issue.
 

kryptticAZ

macrumors 6502a
Original poster
Feb 26, 2007
818
1,104
Phoenix, AZ

ADMG

macrumors newbie
Oct 22, 2019
1
0
Has anybody updated their monitor firmware and had this issue fixed? I can get access to a PC to update firmware but just wondering if its worth the hassle.
 

grennis

macrumors member
Nov 13, 2016
70
196
I have M3B106 update, even newer, and still having the same problem. Every 30 seconds the macbook chimes, the display comes on momentarily, searches for a signal, goes back to sleep. Again and again, every 30 seconds
 

skit0

macrumors newbie
Apr 2, 2020
1
0
Same issue. MacBook Pro 2017 and Dell 38”. Keeps triggering my office security camera as a motion detection. Super annoying. Pretty sure it has to do with the USB-C connection. Dunno if culprit is MacBook or monitor.
 

mijail

macrumors 6502a
Oct 31, 2010
561
137
I have 2 monitors. The AOC never wakes up, but the Samsung keeps waking up for a few seconds more frequently than once per minute.
The monitors are connected through 2 different USB-C - DisplayPort adapters: the AOC with a Choetech one and the Samsung with an Alogic 4k one.

MBP 15" 2018, no PowerNap nor waking for WiFi, no notifications (Do Not Disturb doesn't help).
 

mijail

macrumors 6502a
Oct 31, 2010
561
137
I just swapped the USB-C - DisplayPort adapters, and now none of the monitors seems to wake up!

So looks like both the adapter and the monitor can be at fault here, and one needs an unlucky combination of them for the problem to appear.
 

shaquillep

macrumors newbie
Jun 26, 2020
1
0
Hey everyone,
I just got off of the phone with Apple support. Was having the same issue you all have described with my BenQ SW321C. Figured out it was Adobe Acrobat Synchronizer in the login items that was causing the MPB 16inch to constantly wake and go right back to sleep.

System Preferences > Users & Groups >Login Items . I deleted Adobe Acrobat Synchronizer from there and now my MBP stays asleep. That's what it was for me, but obviously it could be another application/program doing something similar.
 

kryptticAZ

macrumors 6502a
Original poster
Feb 26, 2007
818
1,104
Phoenix, AZ
My Login Items pane is completely empty, so this isn't the problem for me. I continue to have to to power off the display before I put my MBP to sleep.
 
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