You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

User profile for user: SzariK
SzariK Author
User level: Level 1
29 points

Issue with LG 27UP850-W 4K external screen. "No signal" on MBP 16 M1 Pro.

Hi,


I bought brand new monitor LG 27UP850-W 4K. When I connected it (for the first time) to working MBP 16 M1 Pro via USB-C cable everything worked fine. MBP started charging, LG monitor was running fine. The problems happen when I restart or turn MBP off. During boot-up LG monitor shows "no signal" info and nothing else happens. MBP is not being charged and LG monitor eventually goes to sleep. If I want to see something again on LG monitor I need to turn it off completely and turn it on again. After that MBP starts to see LG, which starts working again, and MBP battery starts charging.


The same issue, also via USB-C, is not happening on Windows machine (Dell laptop). When laptops starts after being turned off LG monitor starts simultaneously.


I have the current version of Monterey - 12.0.1. Do you maybe know how to solve this issue?

Posted on Nov 23, 2021 12:54 PM

Reply

Similar questions

5 replies
User profile for user: SzariK
SzariK Author
User level: Level 1
29 points

Dec 18, 2021 12:59 AM in response to Sonicray

Another bigger thread on the same issue: https://www.reddit.com/r/macmini/comments/ql025a/external_monitor_not_waking_up_issues_solved_with/


Issue is related to USB-C or thunderbolt ports. I have not experienced the same issue on HDMI ports. Moreover, I check and the same issue is happening on MacBook Pro 16" 2019.


I think this is a software related issue as the same monitors works perfectly with Windows machines.

Reply

Issue with LG 27UP850-W 4K external screen. "No signal" on MBP 16 M1 Pro.

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.
Learn more Sign up