How to resolve flickering and unusable external monitors with the new MacBook Pro 16"? Displays have worked with previous MacBook Pros.

I'm seeing a similar behavior.

It usually works. But I had this issue twice today. Usually I'm waking the computer from sleep. The screen on the MBP repeatedly flashes, and nothing happens on the external 4k dell display.

Restarts always seem to fix it (this is not an acceptable solution). I also just tried plugging it into the right hand side USBC port and it worked just fine. Not sure what's up with that. I'm using the CalDigit USB-C pro dock, with display-port. As it's working for now, I'm going to leave it and get back to work, but I don't have a lot of confidence in this solution always working.

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Macbook Pro 16"

2.4 GHz 8-Core Intel Core i9

64 GB 2667 MHz DDR4

AMD Radeon Pro 5500M 8 GB

Intel UHD Graphics 630 1536 MB

Andystrandquist wrote

:... Also, it stopped charging as well after going to sleep.

If you are charging with an external dock rather than the Apple power adapter, it probably sent a "go to sleep" signal to the dock when it went to sleep. Use the Apple Power adapter for best results.

If you are using HDMI, which was invented for HD TV sets, it is being stretched to the breaking point by hi resolution displays. There is more than little black magic getting HDMI to work at higher than HD resolutions -- everything must be perfect, and the cables must be exceptional.

If your display has a DisplayPort family input, using that would be superior and far less trouble.

Indeed, I tried a thunderbolt cable and mini display port from thunderbolt with the same issue. This is a hardware software issue. I had no issue with my other Mac. This is a MacBook 2019 16 inch issue. All varieties have issues.

Wanted to update on my issue - I was connecting my monitor through usb-c dock with bunch of ports. I bought a hdmi adapter (apple OEM as well QGeeM usb-c to hdmi adapter) and both of them worked. I don't have any flicker or other issues. There must be some issue with docks and software/hardware interaction with MacBook 16". Now, I need 2 dongles - one dedicated to the hdmi adapter for monitor and another for the rest of the stuff - usb, sd card etc.

Many, many other users are connecting a multitude of displays and using them without the complaint of flickering. [Fan Noise they complain about, but not flickering.]

You should contact Apple Support and arrange to have your MacBook Pro setup evaluated. Take all your gear to your free appointment at an Apple store. You can start with the "Contact Support" link at the top of every forum page.

Many many many many people are posting about this issue here. Did you do a poll or something? How many people do you know personally that are using external displays with the new 16 inch? I don’t know anyone else personally that has the 16 inch. But yes I know plenty of people using a variety of Mac products with infinite display scenarios without issue. I see everyone here is using a new 16 inch and having the issue.

The latest version of MacOS, 10.15.3, appears to have tightened the specs around "legacy" display protocols such as HDMI. Some of these are "suddenly" not working any more.

HDMI was invented for HD TV sets, and its use for higher resolutions has always required a bit of black magic. Even when correctly specified adapters and cables are used, it sometimes fails to produce an adequate picture or falls back to 30 Hz refresh rate, or flickers.

I have always recommended that, if possible, use DisplayPort family to connect your displays.

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If you use a Hub to connect your display using "legacy" protocols, many of these are using DisplayLink technology (custom chips and custom software). MacOS has changed the way Extensions can get access to the system, and DisplayLink has had to re-write their software for most recent MacOS. If your Hub required a driver originally, it may require a new driver to function properly today.

https://www.DisplayLink.com

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This issue is not just hdmi. When I used display port, flickering was present as well with an external usb-c dock. There is certainly either a power/hardware issue with new MacBook 16” or a software compatibility issue in external docks and MacBook Pro. The problem seem to have gone when I used a hdmi cable to directly connect to monitor or an hdmi adapter.

plkris--

When eliminating the dock eliminates the issue, What you are saying is that you don't have a MacBook Pro problem, you have a DOCK problem.

There are many different approaches taken by the many different Docks. Some use DisplayLink technology, and are having a hard time right now.

There’s no reason then why it should work with prev gen MacBook and/or Mac mini. There’s definitely an issue from 16” MacBook side. Also, the display works fine in safe mode. This again tells me that it is not a dock issue - it is something from MacBook

Same issue with WD-15 Dock and even if I use an apple USB-C to HDMI converter the issue exists.

Its a Shame that even a Samsung phone connect to the same setup works as Samsung Dex but an Apple MacBook pro 16" does not work. Even after trying to sell bunch of adapters they can't get it working properly.

If your aock uses DisplayLlink chips and software internally (includes most docks that require a Driver), to produce a "legacy" display Interface (other than DisplayPort) its Driver can not load under 10.15 Catalina, and you may need to get a new driver from the manufacturer or DisplayLink.com

Having the same issue. At first I thought it was the Hyperdrive USB-C hub I was using. Tried two different Hyperdrive models and had the same problem:

When I first turn on the MacBook Pro 16" it wakes up the external monitor as well (Asus PA248) which is connected via HDMI cable. But often after the computer goes to sleep, and I wake it up, the external monitor and MacBook monitors start flashing on and off until I unplug the external. So I ordered a USB-C to DisplayPort cable, and I'm having the exact same issue. Monitor always worked fine on my Lenovo PC and previous 2015 MacBook Pro 15" before now. So I'm assuming it's the MacBook that is having the issue.

If I restart the MacBook, the problem ceases. But I don't want to restart my Mac every time I step away for a few hours, or leave the Mac running 24/7.

I have this same issue. I just got my 16" 2019 MacBook Pro 3 days ago. Previously I had a 15" 2016 model. I migrated from the 2016 to the 2019 via Migration Assistant so the software setup is fairly identical. I never had this issue with the 2016. Everything is the same (software, hub, monitor, cables). The only thing that has changed in my setup is the physical laptop hardware.

I have a USB-C Hub with a monitor attached via HDMI. When I leave the 2019 MacBook overnight (and it goes into sleep mode), attempting to wake the machine results in a flickering loop where it's trying to initialize the displays over and over. If I unplug the USB-C hub (and thereby the external Monitor and everything else) the MacBook wakes fine. However, once I plug the hub back in I start getting the flickering loop again. Rebooting is the only thing that lets me use the hub/external monitor again. Again, this never happened with the 2016 on an identical setup. There is clearly an issue with the 16" 2019 MacBook Pro. My hope right now is that it's not a hardware issue and they can fix it through software. Other than this issue I love the machine so far.

For what it's worth I have a LetsCom USBC002 hub and the monitor is a Philips PHL 276E9Q. My MacBook has the AMD Radeon Pro 5500M 8GB graphics hardware.