I think it's getting worse - having to power cycle the Z27 multiple times a day now.
Have tried firmware reset on the monitor, no change. Different cables don't seem to make any difference either.
I will seek a replacement from HP if I can't get this working better...
MacBook Pro 16″, macOS 10.15
Interestingly enough, Big Sur B3 does not seem to have this problem. MacBook wakes up, and a moment later (couple of seconds) the Z27 wakes up.
This suggests it's a problem on the MacOS side with Catalina. I did think it got worse since earlier this year...
so a way not to power cycle but still annoying, you just have to wake the monitor by pushing one of the buttons to the left of the power button. Once the light turns from yellow to white, then wake up the Mac and the screen is back. There has to be a better way than this. I'm using the USB C / Thunderbolt 3 cable that came with the monitor.
Hi Jan Z,
Thank you for contacting Apple Support Communities. Based on what you stated, it seems like an external display is not waking from sleep.
If your Mac doesn't sleep or wake when expected
"Detect your display
If you're using an external display, sleep and wake your Mac to make it check for connected displays:
If you're using more than one display, and you can see the image on one of the displays, you can also use Displays preferences to check for connected displays."
Get help with video issues on external displays connected to your Mac
Please don't hesitate to let us know if the steps resolved your issue or if you need additional assistance.
Cheers.
I have the same issue. The Z27 is connected and is set up via the display preferences. However, whenever the iMac 27" (just received 4 weeks ago) goes to into sleep mode and the Z27 also goes to sleep mode, the iMac wakes up but the monitor doesn't. I need to power cycle the monitor. The response provided to @Jan Z doesn't seem to address the sleep / awake issue. Is there a setting that needs to be adjusted on the iMac? I'm also checking with HP to see if it's a monitor issue.
Yup, first response misses the point. MacBook wakes up, recognizes the Z27 (shift desktop to it!), but the monitor does not recognize the signal - it remains in sleep mode. Manually switching input does not help. Putting the MacBook back to sleep / closing/opening the lid does not correct this. Power cycling the Z27 makes it work.
Two data points, though these might not be reliable: I have not seen this behavior when running Big Sur (suggesting a MacOS issue?), and this appears to have gotten worse (again, maybe some newly introduced Catalina issue???)
To be on the safe side I might replace the Z27 and see what happens.
HP Z27 does not wake up from sleep MBPro 16
