LG 4K 32un880-b M1 Mini USB-C - Big Sur 11.5.2

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Level 1

6 points

LG 4K 32un880-b M1 Mini USB-C - Big Sur 11.5.2

I bought the LG 4K 32Un880b to use with the new mini M1 back in February. I hoped to connect using usb-c but it didn't work and it was all over the internet.

skip to this week, August 10th, I got a new standing desk and was redoing all the cables and decided to try again. Same USB-C cable (the one that came with the monitor) connected to the mini M1, and it worked perfectly. but today, 1 day after, I decided to update the the latest Big Sur 11.5.2. Right after the update, I am getting the "no signal" over usb-c again.

Clearly, this is a software issue, Apple please fix it!!!!!

Mac mini, macOS 11.5

Posted on Aug 11, 2021 3:29 PM

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Answer 1

VikingOSX

Level 10

123,266 points

Aug 11, 2021 4:02 PM in response to BadPuppy

I have been using this particular LG display since Nov 2020 and I connect my M1 mini to it using a Belkin UltraHD High-Speed HDMI 2.1 cable. It has been completely reliable. Belkin also has a USB-C to HDMI UltraHD 4K HDR adapter that I have also tested with that cable and is just as reliable as previous, except for the additional cost to do something that HDMI <-> HDMI can do for the cable cost.

You may continue to experience USB-C <-> USB-C issues. The LG supplied cable raised my suspicions when I saw it, even though I had already planned on an HDMI direct solution before the display arrived.

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Answer 2

den.thed

Level 10

90,988 points

Aug 11, 2021 3:41 PM in response to BadPuppy

Try using the other Mac Mini's USB-C port.

Try a different USB-C cable than the one that came with the display.

https://www.apple.com/shop/product/MQ4H2AM/A/thunderbolt-3-usb%E2%80%91c-cable-08-m

https://www.amazon.com/Thunderbolt-iWiner-Compatible-Alienware-More-2-3Ft/dp/B08R1LPKHG/ref=sr_1_12_sspa?

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Answer 3

den.thed

Level 10

90,988 points

Aug 11, 2021 4:32 PM in response to BadPuppy

I missed the fact that display has HDMI input and VikingOSX is spot on. I would also switch that display over to HDMI using a Premium Certified HDMI cable instead of USB-C.

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Answer 4

den.thed

Level 10

90,988 points

Aug 11, 2021 9:29 PM in response to BadPuppy

Use both HDMI and USB-C cables with that display.

An HDMI cable for the video connection and a USB-C cable for the built-in hub connection.

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Answer 5

den.thed

Level 10

90,988 points

Aug 12, 2021 6:55 AM in response to BadPuppy

Establish the HDMI connections first and then connect the USB cable as suggested.

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Answer 6

BadPuppy Author

Level 1

6 points

Aug 11, 2021 3:58 PM in response to den.thed

Tried the other port, nada.

I am willing to try another cable, sure. Though the one that came with the display is supposed to be top quality. And the fact that it worked 1 day perfectly...

Also this is a pretty wide spread issue, I haven't found anything online that someone had permanently resolved the issue for this particular monitor over USB-C connection. And it's such a popular monitor too.....

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Answer 7

BadPuppy Author

Level 1

6 points

Aug 11, 2021 8:19 PM in response to VikingOSX

Unfortunately using HDMI miss out one important thing: the USB ports on the back of the monitor will not be powered and serve as additional ports for the host computer unless the it's powered by the host PC using USB-C. See below quote from the monitor's user manual.

I bought the Mini knowing that it doesn't have enough ports, and the I bought the monitor to compensate for that. Without a USBC connection from the host mini, I can't even power a USB powered desk lamp, let along being able to transfer data from the mini.

Connecting Peripherals

USB Device connection

The USB port on the product functions as a USB hub.

NOTE

It is recommended you install all Windows Updates to keep your Windows up-to-date before connecting to the product for use.
Peripheral devices are sold separately.
A keyboard, mouse, or USB device can be connected to the USB port.
The charging speed may vary depending on the device.
To use USB Downstream port of monitor, user must connect Upstream port of monitor to Host PC using USB
C-C or USB C-A cable.
When the USB C-C cable is connected between Upstream port of monitor and Host PC, the Downstream port
of monitor support USB 2.0 device.
When the USB C-A cable is connected between Upstream port of monitor and Host PC, the Downstream port of monitor support USB 3.0 device. However, Host PC must support USB 3.0 function.

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Answer 8

VikingOSX

Level 10

123,266 points

Aug 12, 2021 8:50 AM in response to BadPuppy

LG probably wrote that manual entry with Windows users in mind. With the exception of the USB-C cabling conundrum, I solved all of your bullets above by purchasing a $30 USB3.1 Gen 2 4-port hub that I connect directly to the M1 mini. The only other productive cabling connection was that mentioned Belkin HDMI 2.1 cable.

I think you are whipping a dead horse with that USB-C solution.

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Answer 9

Aug 12, 2021 6:04 AM in response to BadPuppy

If you connect the USB-C port on the display to the USB-A ports on the Mini, the hub in the display will function as a USB3 hub. It says so right in the description you posted:

"When the USB C-A cable is connected between Upstream port of monitor and Host PC, the Downstream port of monitor support USB 3.0 device. However, Host PC must support USB 3.0 function."

So, you can connect the display via HDMI and still have functional USB ports on the display.

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Answer 10

BadPuppy Author

Level 1

6 points

Aug 11, 2021 10:15 PM in response to den.thed

how? have you actually tried it?

I have both HDMI and USB-C connected. if I switch to the HDMI connection, it does not power the USB ports on the back of the monitor......

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LG 4K 32un880-b M1 Mini USB-C - Big Sur 11.5.2

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