External monitor connected to 5K iMac won't wake from sleep

[HoosierInFL]

I bought the late 2015 5k iMac and plugged a 27" Asus monitor into it via HDMI to mini display port adapter. The external monitor works fine until I put the screens to sleep. When I wake up the iMac screen, the external monitor does not wake up. I have to turn it off/on again to get it to work.

Any ideas on how to fix this?

Thanks.

 

[spanishtorero]

I have had the same problem with a Eizo EV3237 via Displayport. I have solved the problem changing a display option: a function called "HPD Control" to on, in my case DP HPD control.

 

[HoosierInFL]

I was able to fix this problem by purchasing an active mini display port to hdmi adapter.

 

[double329]

I use my iMac with Samsung 27" via display port. It seems to be working just fine. It when to sleep and woke up as expected.

 

[HenryAZ]

I have had the same problem with a Eizo EV3237 via Displayport. I have solved the problem changing a display option: a function called "HPD Control" to on, in my case DP HPD control.

Where do you find this option, to be able to change it?

 

[spanishtorero]

Where do you find this option, to be able to change it?

Administrator settings, monitor manual Chapter 4 page 35:

http://www.eizoglobal.com/support/db/files/manuals/03V25103C1/UM-03V25103C1-EN.pdf

Seems it's important the displayport - mini display port cable. You must use a good quality cable. I'm using an Eizo PM 200 cable.

 

[HenryAZ]

Administrator settings, monitor manual Chapter 4 page 35:

http://www.eizoglobal.com/support/db/files/manuals/03V25103C1/UM-03V25103C1-EN.pdf

Seems it's important the displayport - mini display port cable. You must use a good quality cable. I'm using an Eizo PM 200 cable.

Thanks. Since I wrote that, I had been in touch with Eizo tech support, and they pointed me to the Administrator settings menu, which solved the wake-up problem. I now have that manual PDF saved, as well.

Do you see the boot screens when your Mac is booting up? For example, does holding down the Option key give you boot options, or does the Eizo just go into Energy Saving Mode and not show anything until the OS is fully loaded?

 

[spanishtorero]

Thanks. Since I wrote that, I had been in touch with Eizo tech support, and they pointed me to the Administrator settings menu, which solved the wake-up problem. I now have that manual PDF saved, as well.

Do you see the boot screens when your Mac is booting up? For example, does holding down the Option key give you boot options, or does the Eizo just go into Energy Saving Mode and not show anything until the OS is fully loaded?

No, the Eizo exits from Energy Saving in login screen and the Eizo doesn't start when I do holding down the option key...seems that in boot screen only works the iMac pannel.

 

[HenryAZ]

No, the Eizo exits from Energy Saving in login screen and the Eizo doesn't start when I do holding down the option key...seems that in boot screen only works the iMac pannel.

I did discover that using an HDMI connection provides full boot screen access. The monitor is detected right from the start. Of course you only run at 30Hz over HDMI, but using that cable temporarily could be handy for access to boot options, and you can switch back to Displayport at any time for the regular 60Hz.

 

[HenryAZ]

I did discover that using an HDMI connection provides full boot screen access. The monitor is detected right from the start. Of course you only run at 30Hz over HDMI, but using that cable temporarily could be handy for access to boot options, and you can switch back to Displayport at any time for the regular 60Hz.

Never mind. I just realized this is the iMac forum, and you are running the Eizo panel as a second monitor to your iMac, which does not have any HDMI ports. For me, the Eizo is my main (and only) screen for a Mac Pro.

 

[spanishtorero]

Never mind. I just realized this is the iMac forum, and you are running the Eizo panel as a second monitor to your iMac, which does not have any HDMI ports. For me, the Eizo is my main (and only) screen for a Mac Pro.

Have you tried to change the displayport to displayport 1.1 in eizo settings?

The boot screen problem is reported in some eizo support documentos, for example:

http://www.eizoglobal.com/support/compatibility/pc/quadro_k5000_mac_4k_monitors/index.html

 

[HenryAZ]

Have you tried to change the displayport to displayport 1.1 in eizo settings?
QUOTE]

Yes, I did try that. It dropped the resolution from 60Hz to 30Hz, and I didn't go any further with that. Even if it does solve the boot screen issue, I am not running at 30Hz. I at least have the option of plugging in my HDMI cable to boot up with for boot screen options, which I really do not need all that often.