macOS Monterey 12.4 (21F79) - Unable to recognize external monitor (LG)

Question

Level 1

6 points

macOS Monterey 12.4 (21F79) - Unable to recognize external monitor (LG)

My MacBook Pro (16-inch, 2021) is no longer detecting the LG 38UC99-W external Monitor after the software update. Prior to update, the monitor is connected to the MBP with USB-C cable. After reading what some other people had posted regarding this issue from earlier updates, I tried reconnecting the USB-C cable and unplugged the power source to the monitor. None of it worked. Does anyone have the same issue after updating the the lastest Monterey OS? And does anybody have solution to this? Thanks!

MacBook Pro (2020 and later)

Posted on May 27, 2022 5:32 PM

Reply

Answer 1

faith185

Community Specialist

May 28, 2022 12:30 PM in response to Cali_NW_MRY

Hi Cali_NW_MRY,

Welcome to Apple Support Communities. Great troubleshooting so far. Check out If your external display isn't detected or appears blurry when connected to your Mac which has a couple more tips that might help.

If the same continues, try resetting the SMC which can help if the issue is power-related- How to reset the SMC of your Mac.

Best of luck.

Reply

Answer 2

destiny241

Community Specialist

Jun 9, 2022 6:12 AM in response to Cali_NW_MRY

Hello Cali_NW_MRY,

Have you installed the latest driver for the display? Looks like LG recently released a driver for Mac on 5/31/22: https://www.lg.com/support/product/lg-38UC99-W.AUS You'll see the driver on the right side of the website under Software & Drivers.

Once you've installed the driver, reconnect the display and attempt to test it out.

Let us know if that helps to solve this, cheers.

Reply

Answer 3

Cali_NW_MRY Author

Level 1

6 points

Jun 9, 2022 1:24 PM in response to destiny241

Thank you for your response, but the software wasn't a firmware for the monitor. It was on board LG software to control the monitor.

I tried it anyway, but it still doesn't work. The problem is the laptop does not detect the monitor at all! The USB-C connector from the monitor also charges the laptop. So when I plugged it. The laptop usually pick up the signal and get charged. Now nothing happens!

Reply

Answer 4

Cali_NW_MRY Author

Level 1

6 points

Jun 8, 2022 4:12 PM in response to faith185

It did not resolve the issue.

Reply

Answer 5

Jun 9, 2022 10:04 AM in response to Cali_NW_MRY

I'm also having this exact problem with 2 different monitors and two different connection types. Both were working fine until the day after my Macbook updated.

Reply

Answer 6

K_Faith

Community Specialist

Jun 9, 2022 1:30 PM in response to Cali_NW_MRY

We understand Cali_NW_MRY,

At this point, we recommend reaching out to Apple for further assistance in resolving this issue here: Get Support

Cheers!

Reply

Answer 7

Jul 4, 2022 2:14 AM in response to Cali_NW_MRY

Same issue as above! External monitor no longer working with USB-C. Also, my Ethernet port adapter not reading either.

Reply

macOS Monterey 12.4 (21F79) - Unable to recognize external monitor (LG)

Similar questions