Ever since getting my new monitor (a Dell U3225QE — a nice IPS LCD after some OLED issues) I’ve been having problems with it not going to sleep. But that’s not usually a monitor problem, especially as I could manually put it to sleep… So what’s keeping macOS from putting it to sleep?
Well, thankfully with pmset one can see what’s going on:
c0nsumer@mini ~ % pmset -g
System-wide power settings:
Currently in use:
standby 0
Sleep On Power Button 1
autorestart 0
powernap 1
networkoversleep 0
disksleep 10
sleep 0 (sleep prevented by backupd-helper, powerd, backupd, coreaudiod, coreaudiod)
ttyskeepawake 1
displaysleep 10 (display sleep prevented by CEPHtmlEngine)
tcpkeepalive 1
powermode 0
womp 1
c0nsumer@mini ~ %There we go, seems CEPHtmlEngine is preventing the display from sleeping. So what is it?
c0nsumer@mini ~ % pmset -g assertions | grep CEPHtmlEngine
pid 15995(CEPHtmlEngine): [0x00038aae00059926] 46:44:27 NoDisplaySleepAssertion named: "Video Wake Lock"
c0nsumer@mini ~ % ps aux | grep 15995
c0nsumer 15995 3.4 0.1 412316000 64256 ?? R Sat08AM 128:30.24 /Applications/Adobe Illustrator 2025/Adobe Illustrator.app/Contents/MacOS/CEPHtmlEngine/CEPHtmlEngine.app/Contents/MacOS/CEPHtmlEngine b27716d6-c14c-49e4-8612-b5ab9de9bdf4 1103d4a0-8756-40b2-af81-5646ba80756f ILST 29.8.4 com.adobe.illustrator.OnBoarding 1 /Applications/Adobe Illustrator 2025/Adobe Illustrator.app/Contents/Required/CEP/extensions/com.adobe.illustrator.OnBoarding 32 e30= en_US 1 -11316397 0
c0nsumer 58444 0.0 0.0 410724448 1472 s002 S+ 7:14AM 0:00.00 grep 15995
c0nsumer@mini ~ %Really? Illustrator? Huh… I have been working on a new map of Bloomer Park (in anticipation of the forthcoming Clinton River Oaks Park changes) for CRAMBA and leaving it open in the background… I guess that’s it.
And strangely, closing and re-launching Illustrator made the assertion go away. And now the problem is gone.
Oh, Adobe…
At least it’s easy to tell why it was happening.
(This is Adobe Illustrator v29.8.4 on macOS Sequoia 15.7.3.)