Acer B286HK UHD not working with new Macbook

Question

Level 1

8 points

Acer B286HK UHD not working with new Macbook

I have an Acer B286HK UHD display, a 12" 1.3 ghz Macbook, and the Apple 3-way digital USB-C adapter. I know the Mac and adapter work because I have a Samsung UHD display at hone and it works perfectly. I know the Acer and HDMI cable are good. Until last week, I used my 2013 Macbook Pro with no problem. I also connected a Windblown laptop, which also worked fine. Display Settings will not allow changing the display speed from the default of 30hz.

MacBook Pro (Retina, 15-inch, Early 2013), OS X Mountain Lion (10.8.5), i-Tunes, i-Phone

Posted on Jul 8, 2015 11:54 AM

Reply

Answer 1

egard

Level 1

4 points

Mar 28, 2017 9:50 AM in response to markrtallman

SOLVED!

1) Apple menu > System Preferences > Displays

2) Move cursor to external monitor window and click on the "Display" tab

3) ***Press the Option key while you click Scaled***

4) Select "Show low resolution modes"

5) Change Refresh Rate from 30Hz to 24Hz, or choose a lower resolution @30Hz

I suspect this problem is limited to HDMI, and that a DisplayPort cable will enable full 4K @ 60Hz, but I'm still waiting for my new dock to test this.

Reply

Answer 2

markrtallman Author

Level 1

8 points

Jul 9, 2015 11:47 AM in response to markrtallman

I had changed DP mode to 1.1, then back to 1.2 on the display. Each time, I shut down my Macbook, doing a PRAM start to pick uo the setting change. I realized my best bet was to change the speed of the signal from the Macbook I then went into the settings on the monitor and set ACM to ON. I shut down and did a PRAM start. After I had done this, Display settings had the speed. I changed it from the default of 30hz to 24z. This not only solved the flickering problem, but it increased my resolution many fold and added much better color content. The Macbook needs MST for a UHD display. Either the combination of DP 1.2 and ACM ON gave MST via an Easter Egg, or the combination fooled the Macbook into thinking MST is ON. I really do not care which. It did add speed settings to Display Settings, allowed me to change to 24hz, and fix the flickering problem.

Reply