External Monitor Disconnects and Flickers with Type-C to DisplayPort on MacBook Pro (M1 Pro)

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Level 1

4 points

External Monitor Disconnects and Flickers with Type-C to DisplayPort on MacBook Pro (M1 Pro)

I’m experiencing issues with my external monitor when using a Type-C to DisplayPort (DP) connection with my MacBook Pro 16-inch (M1 Pro). The monitor is a Samsung Viewfinity, and I notice the following problems:

Whenever I plug in or unplug the MacBook’s charger, the external monitor briefly disconnects and reconnects (with a momentary flicker), which is disruptive.
When the MacBook goes to sleep, the external monitor intermittently wakes up and then goes back to sleep repeatedly, without any action on my part.

These issues do not occur when I connect the MacBook to the monitor using an HDMI-to-HDMI cable, which provides a stable connection.

Could this be a compatibility issue with the Type-C to DP connection, or is there an adjustment in settings or firmware update that could help stabilize the connection? Thank you!

MacBook Pro 16″, macOS 14.7

Posted on Oct 25, 2024 10:10 AM

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Answer 1

Oct 26, 2024 10:41 AM in response to mohit0233

the stuff I was fishing for is

Resolution: 4K

Inputs:

HDMI

1 version 2.0 (up to 4K@60 Hz on a Certified Premium or ULTRA cable)

Display Port

1 version 1.2 (no compression, but supports up to 4K @60 Hz with HDR)

If connecting via a USB-C to DisplayPort cable/adapter, the total allowable length from the USB end to the conversion electronics is one meter. Cables longer than that will generally be unreliable.

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Answer 2

Oct 26, 2024 12:42 PM in response to mohit0233

Recent versions of MacOS detect errors in transmitting data to the display, and shut it off when it detects errors (whose fundamental causes might be tiny power fluctuations, or anything else).

The way to fix ALL such problems is to get a more robust connection. a really easy way to attain that is by using an appropriately short cable. Since the switching speeds for data at these resolution are nearly the electrical limit of switching speeds to electronic devices, the long term fix is to change the game by using fiber optics, or by using a modulated signal (multiple different patterns per signing interval) instead of a baseband signal.

Or switching to Windows, which has no standards for good displays.

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Answer 3

mohit0233 Author

Level 1

4 points

Oct 26, 2024 9:12 AM in response to Grant Bennet-Alder

Please find the monitor info below:

The full model code is LS27A800NMWXXL.

Amazon Link: Samsung 27-inch (68.47cm) 3840 X 2160 Pixels 4K UHD Monitor, IPS, Bezel-Less Design, HAS, 1 Billion Colors, HDR10, Intelligent Eye Care, AMD FreeSync, FSC-Certified, (‎LS27A800NMWXXL, Black)

You can view or download the official manual here: Samsung Monitor Manual.

In MacOS System Information (under Graphics/Display), it shows up as "LS27A80" with the following details:

Resolution: 3840 x 2160 (2160p/4K UHD 1 - Ultra High Definition)
UI Looks like: 1920 x 1080 @ 60.00Hz
Mirror: Off
Online: Yes
Rotation: Supported

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Answer 4

mohit0233 Author

Level 1

4 points

Oct 26, 2024 11:30 AM in response to Grant Bennet-Alder

Thank you for the helpful information on the recommended cable length for USB-C to DisplayPort connections.

I’m currently using a CableCreation 6.6 ft USB-C to DisplayPort cable, compatible with 4K@60Hz, which appears to be a bit longer than the recommended maximum length of one meter for a stable connection. Here’s the Amazon link for reference: CableCreation USB-C to DisplayPort Cable.

Is there any way to minimize the flickering or blinking I experience? What could be the suspected reasons that might cause the external monitor to flicker when I connect or disconnect my MacBook’s charger?

Also, if the current cable is still considered a bit too long, is there anything I can do to make the connection more stable, like firmware updates, adapters, or settings adjustments?

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Answer 5

Oct 25, 2024 5:06 PM in response to mohit0233

which model viewfinity, and a link to its specs, please

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