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

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.

Hi,

To add to the discussion. I purchased an appleUSB-C to Digital AV dongle. This connects to all my displays without the flicker I had with my Satechi hub. My MBP is the 2019 16" version.

Hopefully this is useful info for someone.

Update: I'm not a pro but I was able to get my hands on several different (all Dell) hubs from my wife's work. All had the same issue. I know it seems like a port/driver issue but it seems that a lot of people are having similar problems with these hubs that don't push enough wattage (That Dell pushes like 65w I think). This doesn't explain it for folks with LG Ultrafines. I hooked up my Dell with a temporary solution/ and Anker 7 in 1 USB-C adapter. I'm in business. Now I'm considering upgrading to one of these Dells that they just announced at CES. Run 90w USB-C geared towards running/charging new MacBook Pros.

to get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display.

This query is only sent at certain times:

• at startup

• at wake from sleep

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• on invoking Option-(Detect Display) button in Displays preferences --especially on a MacBook Pro

so try doing some of those things and see if the display comes alive.

Modern Displays with multiple ports are sometimes busy scanning the other ports, looking for an input, and miss the query from the Mac. They need to pay attention to the port you are actually using, or they will miss the query.

Some displays have On-Screen Display settings that can be used to tell the display a computer is attached on a certain port, or a certain port should be highest priority. Changing those may make your display more responsive.

Some displays include their own private "sleep" settings for the display alone. This can allow the display to enter its own sleep mode, on top of the Mac's not sending it data. A display that is sleeping on its own cannot respond to the Mac's query, and will stay dark.

Experiment: Use Mirror displays to connect both the flickering display and the internal display together.

If the flickering follows onto the Internal display, you likely have a Hardware problem in the MacBook Pro.

If the external still flickers when mirrored, but the internal is fine, it may be a ThunderBolt port problem or a cabling problem.

Experiment: Use Mirror displays to connect both the flickering display and the internal display together.

If the flickering follows onto the Internal display, you likely have a Hardware problem in the MacBook Pro.

If the external still flickers when mirrored, but the internal is fine, it may be a ThunderBolt port problem or a cabling problem.

MacBook Pro 15-in or 16-in features dual graphics chips. The Internal display can run off Integrated graphics, but when you connect an external display, the Discrete graphics processor is always used. There is not even any wiring that allows the Integrated graphics chip to be used for an external display.

So when you are complaining about the External display, you are also implicating the Discrete graphics processor. A Hardware failure in that graphics chip could produce the symptoms described.

When you invoke Mirror Displays, they are physically connected. The Mac always uses EXACTLY the same display buffer and rasterizer circuitry for both displays. So if you mirror a flickering display to the built-in display, the problem may become a problem for the Internal display as well. (When mirroring, a different compromise resolution that both displays claim to support may be used.)

rtgtrovador--

Although there is a little bit of circuitry in the Mac that COULD be problematic, if you are doing the suggested Mirror display experiment and the issue follows the external display and does NOT appear on the Internal display (using the same graphics generator in the display chip) you have almost certainly isolated the problem to cables and adapters or the display itself.

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.

The maker suggests connecting the power adapter when using that Letscom USBC002 hub. ¿Are you?

Apple recently released an update for the 16 inch; since then I have had better luck connecting to my external via HDMI. Better being the key, it still has issues when I connect initially but will eventually work. I will plug it in and then remove and replug in the cable and it'll begin to work. This resolution only works if I have my MacBook open and awake/powered on first. It does wake up using my external keyboard or mouse but only after falling asleep while plugged in and used initially. Strange stuff

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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The Apple power supply is 94 or 96 watts, the LG 27" is only 85 watts. I've noticed under heavy load, where the fans spin up, that the battery drops below 100%. I am now using the Apple supplied power supply and the monitor is just supplying video via the thunderbolt 3 cable.