2012 Mac mini - Won't wake monitor via DisplayPort

[eddie0]

It is somewhat a real archievement… conserving a real bug over time, hardware and many changes in the os……..

 

[atticlight]

Just ran into similar version of this problem. I had multiple 2012 Mac Minis that would power up and output signal through Mini Display Port. In my case if I rebooted or put to sleep, MDP would no longer work and multiple reboots would not solve it. Resetting PRAM/NVRAM didn't work, nor did SMC. I even removed the RAM, rebooted to trigger ram error, reinstalled RAM, then rebooted. This trick yielded inconsistent results. Some of the minis would work and others wouldn't. Or it would fix it once but not a second time.

SOLUTION: I changed power source (different circuit) and everything worked fine again. MDP on all minis are sending good clean consistent signal again. Only thing that actually changed was what outlet I was using. Don't know if this will help OP or anyone else out there, but thought I'd share what worked for me. Good luck!

 

[BingClawsby]

Happens every so once in a while on my 2012. Two displays, same model, one with the mdp , the other hdmi. Sometimes the mdp one, sometimes the hdmi. Annoying if it's the main menu whatchamacallit. Then I have to turn the machine off with the power button, cuz eff me if I could ever get any of the shutdown/restart key commands to ever work on this thing... and I use the mac keyboard

 

[patrick_21]

Also having this problem after updating my monitors (Lenovo Thinkvision LEN P27u-10 Display and LEN T22i-10 Display), one by display port (mini display port to display port) and the other by HDMI. As with others, my main issue was having to reboot the computer to get it to detect the display. Does not seem like apple will be making any updates to Mac Mini 2012. I did notice, however, that the next morning it did detect my display port monitor, briefly, so here is my interim solution...

Interim Solution (without having to reboot) when it is in power saving mode:
Go to System Preferences>Energy Saver, change settings to "computer sleep" and "display sleep" to 1 minute. Turn off displays, leave Display port and HDMI connected. Put computer to sleep (Command+Option+eject), then wait one minute. Turn on Display Port monitor. Wake computer, and as someone mentioned above computer seems to go through a process to reset monitor (perhaps someone else has a more technical explanation). Bingo, display port connected. Then, turn on HDMI display and good to go (no need to reboot computer). Oh, and then change back your Energy Saver settings to whatever you want.

It is cumbersome, but better than having to reboot computer every time it sleeps.

This Interim Solution worked on my Mac Mini 2012 Catalina 10.15.7 using Display port to connect to an Asus PB278Q.

Normally neither the computer nor the monitor was set to ever sleep, I'd just turn off the monitor when I was leaving my desk. When turned back on the monitor sometimes didn't sense a DisplayPort signal, so it would "helpfully" switch to the HDMI signal from another computer. In a pinch I would use screen sharing from that other computer to finish the task I was in the middle of before restarting. Somehow it seems significant that screen sharing would work but not the display port.

With this Interim Solution I didn't have to restart the computer to get it to sense the monitor.

 

[kchai007]

Having this issue today in August 2021 with stuff all bought new this year:

• Mac Mini M1, 2020, Big Sur 11.5.1 (20G80)
• Samsung Odyssey LC27G7xT
• Direct DisplayPort cable connection, no adapters

Sorry, I'm running out of discreet words.

Thanks for the post. I'll get a MacBook Air then. This (the issue) is very sad. I tried a USB-video adapter with DisplayLink DL-3500 chipset (WL-UG3501H) on the Mac Mini Late 2012, it cannot deliver 2560x1440. 1920x1080 works fine. The same adapter works perfectly on Chromebook or MS Surface to deliver 2560x1440.

 

[A4orce84]

Thanks everyone for your comments and feedback, it is greatly appreciated (I'm the OP).

Question - Anyone seeing similiar issues with the M1 Mac Mini?

 

[zaxanoid]

Happens every so once in a while on my 2012. Two displays, same model, one with the mdp , the other hdmi. Sometimes the mdp one, sometimes the hdmi. Annoying if it's the main menu whatchamacallit. Then I have to turn the machine off with the power button, cuz eff me if I could ever get any of the shutdown/restart key commands to ever work on this thing... and I use the mac keyboard

Same issue here. worse, I am using a Windows keyboard. My only way out seems to be a 2nd cable from the same monitor to the HDMI port, switch to that, and the screen works, then do a "sleep". Switch monitor back to Displayport, and wake using keyboard. At least no more "power button" resets

 

[kchai007]

Thanks for the post. I'll get a MacBook Air then. This (the issue) is very sad. I tried a USB-video adapter with DisplayLink DL-3500 chipset (WL-UG3501H) on the Mac Mini Late 2012, it cannot deliver 2560x1440. 1920x1080 works fine. The same adapter works perfectly on Chromebook or MS Surface to deliver 2560x1440.

I eventually found this solution. This DisplayLink adapter (this one) and DisplayLink driver (Catalina 10.15, Release: 1.5 | Sep 8, 2021). It has been working for 3 days.

The setup bypasses the DP port on Mac Mini itself. For the past 3 days, there is no more blank screen on the QHD monitor (2560x1440)!!