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vkenichi

macrumors newbie
Original poster
Mar 26, 2021
2
0
Hi!

I just bought an LG UltraFine monitor for use with my MacBook Air. It's obviously an older computer that is limited to ThunderBolt 2 connection, whereas the UltraFine requires ThunderBolt 3. From what I understood, I could use a TB2 cable/ TB3 adapter to connect to this display. I had already been using that connection to utilize a CalDigit TS3 with this computer, and it has worked perfectly.

I received the monitor today, and am having issues getting an image to appear on it. I tested it on my GF's newer MacBook Pro (with TB3), and it worked flawlessly. When I connect to my older MacBook air (with the dongle), the computer turns black and adjusts its resolution on the built in display, but no image appears on the UltraFine. When I go into display settings, the LG UF appears and has options I can modify (none of which matter because all I see it black), and I can even play audio through the monitor. So clearly, a connection is being made.

Is there a reason I am not seeing any picture, despite my computer recognizing the UltraFine and the monitor being able to playback audio?

Thanks!
 

Amethyst1

macrumors G3
Oct 28, 2015
9,822
12,241
A 2012 MBA can only do 3840×2160 at 30 Hz (without further ado) which the monitor may not like. 30 Hz, even if it worked, would get very annoying very quickly anyway. What resolution and refresh rate does macOS say it's outputting to the display?
 
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vkenichi

macrumors newbie
Original poster
Mar 26, 2021
2
0
A 2012 MBA can only do 3840×2160 at 30 Hz (without further ado) which the monitor may not like. 30 Hz, even if it worked, would get very annoying very quickly anyway. What resolution and refresh rate does macOS say it's outputting to the display?
I actually cannot access the monitor for the next few days (perhaps I should have started this thread later!), but I recall 'SwitchResX' saying it was outputting at 59 Hz... I can't recall the resolution. I suppose I could follow up on this when I have access to the monitor again, but is there a generally accepted solution to this? Can I force a higher refresh rate on it?

Unfortunately I'm not super apt with the technical details of displays, but I read somewhere online (without proper explanation) that someone with a similar predicament was able to get the monitor to work on their 2012 MBP only when using a Windows partition- that the reason is software related. Does this sound right?
 
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Amethyst1

macrumors G3
Oct 28, 2015
9,822
12,241
Can I force a higher refresh rate on it?

You can try SwitchResX to set up a custom 3840×2160 mode with a 40 Hz refresh rate.

2560×1440 at 60 Hz is also possible but will result in a slightly blurry picture if the monitor upscales it to fill the screen. (If it doesn't there'll be black bars around a centered picture.)

This is assuming the monitor will accept these modes to begin with.
 
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