External monitor flickering Macbook 2016

I was experiencing screen flicker (white fuzzy screen) intermittently and seemed to have found the issue

Background: I did try changing HDMI cables, changed the Thunderbolt port the Apply USB-C adapter was plugged in to, switched power outlet the Samsung power adapter was plugged in to and reseated all plugs and adapter - didn't fix the flicker issue

My setup is:

MacBook Pro late 2016 15" w/ Touchbar

External monitor - Samsung UE590 UHD 4K 28" 2015 model

Connected via Apple USB-C Digital AV Multiport Adapter

The monitor has 2 inputs HDMI 1 and HDMI 2

For some reason when I plugged in to HDMI 1 port on my Samsung monitor my MacBook set the resolution to 1920x1080, set at this resolution I would experience the intermittent screen flicker. I did not realize my MacBook had set the resolution to 1920x1080. As a "hale merry" at my wits end I moved the HDMI cable from HDMI 1 to 2. When I did that the external screen immediately stated the native resolution was 3840x2160 and my MacBook automatically set the resolution to 3840x2160.

Now that the MacBook output Resolution is set to the native 3840x2160 of the external monitor, so far, I have not experienced the screen flicker a single time

If for some reason your MacBook does not automatically switch the resolution to the native external monitor resolution, just click the Apple icon and select System Preferences, Display and click the 4 boxes to get to as close the native external screen resolution you can

Hope this helps someone

I have the same problem and would like a quick solution, given just how much I am now spending on a) mac laptop and b) mac accessories to account for the removal of standard USB and HDMI ports.

Please fix and update as a matter of priority.

I've used multiple laptops and multiple monitors, and the problem persists. Purchased a HooToo HDMI dock/adapter and it works without a single flicker or pop, where I was getting them constantly with the Apple adapter.

Hi HAL_Daddy

This was a really helpful response, thank you.

I have exactly the same set-up. New Macbook 2016, with Samsung UE590 monitor.

It's my daughter's and she wanted the text easier to read so we opted for HDMI 1 and 1920 x 1080.

HOWEVER, we got the constant flickering which was really annoying. Tried various HDMI leads with the official Apple adapter, but it was always the same.

I coaxed her to try the higher resolution, which is what I prefer to work with, and told her she would get used to the resolution. We plugged into HDMI 2 port for native 3840x2160 and not a single flicker.

I think this is quite bad from Apple that you cannot change resolutions without issues.

Nevertheless, very happy there is no more flickering. Although she has to lean slightly forward to see menu and tool options in word as they are quite small.

Best

I am fighting with flickering of external display issue last week. That's the time I've go new MacBook Pro 2016 with TouchBar (13-inch, 2016, Four Thunderbolt 3 Ports, 2,9 GHz Intel Core i5, 8 GB 2133 MHz LPDDR3) and I've tried to connect it to external display, as this is the way I work with the notebook in my office and at home. I have the opportunity to try several displays with different screen sizes, resolutions and input connectors. On some displays there's flickering problem (display goes black and in picture flashes for very short time, can be recognized MacBook's desktop and goes black again, this is repeating on and on). Maybe two times I've got stable full picture of desktop for few seconds, but with corrupted colours, like some RGB-out problem.

So here's is my study:

TV Panasonic Viera TH-37PV7P, HD1080, HDMI to HDMI via SATECHI USB-C adapter - working,no problem

EIZO EV2736W, 2560x1440, LMP USB-C to DVI adapter - working, no problem

EIZO FORIS FX2431, 1920x1200, LMP USB-C to DVI adapter - working, no problem

HP w2207h, 1680x1050, HDMI to HDMI via SATECHI USB-C adapter, LMP USB-C to DVI adapter - flickering both

LG Flatron L2000CE, 1400x1050, LMP USB-C to DVI adapter - flickering

This seems to be interesting issue, because - if it was adapter or firmware problem, it should be problem on all devices, if it was USB-C connector on MacBook - it's the same, it shouldn't work on my old TV or EIZO monitors (FORIS is also pretty old too, the other is last year's).

Before new MacBook Pro I was using MacBook Air 2015 and none of these problems were issued.

I was trying to solve my problem, which is pretty annoying. I've found partial solution, but it still makes me mad.

I connected my home HP w2207h display, 1680x1050, HDMI to HDMI via brand new Hyper Drive USB-C hub. The display started flicker immediatelly. I used MIRROR setting under SYSTEM SETTINGS -> DISPLAYS (so I can change the settings for HP display). Then I've selected Scaled option (instead of Best for display option) for HP w2207 with OPTION key pressed. It revealed lots of display resolutions.

I was trying every one of them and found out, that on 480p and 720p settings the display staeted to work normally. The resolution is too low for this display, can't be used for normal work, but the flickering is gone, picture is clear and stable. It really seems to be driver issue. So don't waste your money buying couples of cables and adapters, it will do nothing. I think we have to wait for Apple to fix it...

I have in my company 2 x 2017 Mac Book Pro with USB-C connected to first MBP connected to Apple Cinema Display and second to Dell U2731 27" monitor.

The adaptor used is an Uptab USB-C to DP in both cases. The adaptor has 3 connections on it: 1) a male USB-C to go into the MBP on one end, and 2) a female USB-C and 3) a female mini-displayport on the other. We had been habitually operating the MBP with power directly into the MBP and leaving port 2) on the Uptab disconnected.

Just experienced an issue where after several weeks of working reliably, the monitor was detected, with the laptop showing the monitor specs in the Display preferences window, but on the monitor itself the "No Display port signal" was shown. Plugging & unplugging would get the MBP into a mode where it was cycling and flashing between black screen & display.

The Uptab adaptor is electronically external display processor in its own right and has quite a bit of electronics on board. When first installed it received its own firmware update. In my opinion (no evidence) repeated plugging & unplugging is not good for this adaptor. It should be left plugged in when possible.

The fix in the end to resolve the issue was to plug power into the Uptab via its USB-C in port. After doing this and then rebooting the MBP it started working reliably again.

I am guessing (again, no evidence, all feels) that the Uptab has some current requirements when its trying to drive the Dell monitor and these are not met when acting in slave mode from the MBP, so supplying power into the Uptab solves this problem. There may also be some kind on small onboard battery on the Uptab which becomes depleted after a time. Whatever the truth, this resolved it for us.

So...I bought a MacBook Pro 13" (2017) with Touch Bar. I have a 34" curved LG Ultra Wide at home and a 28" Samsung Ultra Wide at work. At home everything worked perfectly - no flickering when the external monitor was plugged in. Get to work on Monday - hey presto - Flickering! hence me doing some searching and finding this thread.

Monitor Specs:

LG Monitor 34": 2560x1080

Samsung Monitor 28" : 3840x2160

LG Monitor at home, connected via HDMI and HDMI port 1 on monitor - no issues. Monitor defaulted to its standard resolution when plugged in with the Apple Multi AV adapter.

Samsung monitor at work : connected via HDMI and HDMI port 1 on monitor - ISSUES. flickering every few seconds and every minute or so white screen - just for 1/4 second but enough to drive crazy.

The Samsung seemed to be in right resolution as when tried using the scaled resolution the monitor popped up and said it was adjusting - but still flickered.

I've then moved the cable to plug into HDMI port 2 on the monitor - hey presto - flickering gone! Also immediately I plugged into HDMI port 2 on the monitor the picture/text on the Samsung was very much smaller seeming to indicate the monitor had changed resolution - i.e. at the default resolution for the monitor. When I plugged to the HDMI back into the HDMI port 1 the screen resolution on the monitor went back to its bigger text size and started flickering again. When plugged back into HDMI port 2 - resolution changes and flickering stops.

This seems to indicate that there is something going on between port 1 and port 2 on the monitor. Nothing to do with the MacBook it would seem. The monitor should contain an EDID file which the matchbook reads when the monitor is plugged in which tells the MacBook what resolutions are available and what the default is. For some reason there is a difference between HDMI port 1 and HDMI port 2. I know that HDMI ports on TV sets can be different and some devices will not output their signal when plugged into HDMI 1, but will on HDMI 3 - this due to slightly different configurations on the ports. The TVs also have an EDID file which should be read to see what resolutions etc.

The good news is this seems to indicate it is not hardware, but a driver/config issue. Bad news is we now watch the Monitor manufacturers says it is an Apple issue and Apple say it is monitor issue - leaving us stuck in the middle.

I was using SwitchResX on my 2013 MacBook which worked perfectly on both monitors - using HDMI and into HDMI port 1 on both monitors.

The monitor is flickering because it is not getting correct info in the signal. I would suggest trying the other ports on the monitor or TV per above or trying SwitchResX. I have not tried SwitchResX on the new MacBook - I'll only install it if the issue comes back on HDMI port 2.

This looks like it is something to do with resolutions and refresh rates and depending on the monitor you may be ok or not. On my previous MacBook I installed SwitchResX because the monitor I had before I had the LG 34" used to give a fuzzy picture until installed. I jut never uninstalled it when I got the 34".

Hope this helps narrow down the issues for some of you.

Same issue for me - and solved in the same way - once you have done this I solved my issue by then going to Screen preferences and selected the scaled display for the external - instead of standard. If you select the largest text the monitor starts flickering (it changes the resolution if you select this one - but if you select the middle scaled resolution the resolution stays at the default and the text gets bigger - and no flickering!

Hello Schendstok,

Thank you for using Apple Support Communities.

I understand from your post that you are trying to use an external display with your MacBook, but the monitor is showing a blank screen. I like using external displays with my Mac too. I recommend reviewing the following article to verify if everything meets the system requirements and for some additional troubleshooting steps:

Get help with video issues on external displays connected to your Mac

Best Regards

Schendstok,

You can run a diagnostic on your Mac without having to take it into an Apple Store. Restart your Mac and immediately after you hear the start-up tones, press and hold the D key on the keyboard until you see the diagnostic begin. This article has some additional information about the diagnostics:

Using Apple Diagnostics

Cheers

I am having similar issue on the 2016 MacBook,

but not the 2015 MacBook,

I would say it's either driver or hardware issue.

I have the same random flickering problem. I am running an external display 3440x1440 @50Hz. If I boot the machine with the monitor attached then it works perfectly all day. It seems to only happen after sleep mode. Therefore, I hope it can be fixed via software update....