MacBook Pro 16/Air M1 external USB-C screen turning black - NEC EA271U

[Diwad]

Hey everyone!
I just bought new monitor for my home office setup - NEC EA271U and have some serious issues with it when trying to use USB-C connection.
When it is plugged in it charges the computer just fine, displays screen for about 10s and turns black/no signal, while it is still visible in About this Mac - Displays section as well as in the preferences panel. Mac sees it as connected, I can drag apps there, etc, but the display is not showing anything. I dug through tens of threads regarding external displays problems but no solution.

Using Big Sur 11.1, but saw some posts such issues started appearing since Catalina release.

Things I tried:
- PRAM/NVRAM reset (command + option + P + R)
- three different cables - one I use with my other 4k usb-c monitor, that came with it (LG 27UL850), two 4k@60Hz 10Gbps, c-c cables with 100W PD capabilities
- tried two different Macs - MacBook Pro 16 and MacBook Air M1 - on the M1 it doesn't even show up for 10s
- IN SAFE MODE IT WORKS - but just up to 1920x1080p
- USB-C to HDMI adapter works fine, but its just 30Hz at 4K

I don't want to use any other connection but USB-C.
Anyone of you had similar issues? I literally spent half of the day looking for a solution. On some Polish forums users with same problems told me it must be some Mac OS fault because they are using Windows just fine with same setup.

Maybe some kexts are broken, maybe some PD negotiation going wrong.
Here is displaypolicyd log. maybe you can find some clue there:

2020-12-03 16:05:39.480472+0100: NOTICE: kIOFBNotifyOnlineChange 0x1 fb[ 1 ] -> online, Thu Dec  3 16:05:39 2020
2020-12-03 16:05:39.480541+0100: NOTICE: Update display map to fb[ 1 ] - online
2020-12-03 16:12:45.182066+0100: LinkUpdate: 3.0 event: Remove [1]
2020-12-03 16:12:45.182220+0100: NOTICE: Addr: 3.0 event: Remove [1] source: 0
2020-12-03 16:12:45.182296+0100: NOTICE: Do offline device addr 3.0 flags 0x0
2020-12-03 16:12:45.182348+0100: NOTICE: FB AGDC state FB[1] - OFF
2020-12-03 16:12:45.182624+0100: NOTICE: inject FB[1] change
2020-12-03 16:12:45.464243+0100: NOTICE: kIOFBNotifyOnlineChange 0x3 fb[ 1 ] -> offline, Thu Dec  3 16:12:45 2020
2020-12-03 16:12:45.464315+0100: NOTICE: Update display map to fb[ 1 ] - offline
2020-12-03 16:12:45.464331+0100: NOTICE: Release fb[ 1 ] resources
2020-12-03 16:12:45.464360+0100: NOTICE: Do LT off on port 3
2020-12-03 16:12:45.464574+0100: NOTICE: Port[3] - DP link down
2020-12-03 16:12:52.202259+0100: NOTICE: accepted No_Media_Mode enter, Thu Dec  3 16:12:52 2020
2020-12-03 16:12:52.632042+0100: NOTICE: kIOFBNotifyOnlineChange 0x1 fb[ 0 ] -> offline, Thu Dec  3 16:12:52 2020
2020-12-03 16:12:52.632097+0100: NOTICE: Update display map to fb[ 0 ] - offline
2020-12-03 16:12:52.732468+0100: NOTICE: accepted No_Media_Mode exit, Thu Dec  3 16:12:52 2020
2020-12-03 16:12:52.732607+0100: NOTICE: accepted No_Media_Mode enter, Thu Dec  3 16:12:52 2020
2020-12-03 16:12:53.694129+0100: NOTICE: accepted No_Media_Mode exit, Thu Dec  3 16:12:53 2020
2020-12-03 16:12:54.785965+0100: LinkUpdate: 3.0 event: Remove [1]
2020-12-03 16:12:54.786073+0100: NOTICE: Addr: 3.0 event: Remove [1] source: 0
2020-12-03 16:12:54.950275+0100: NOTICE: accepted No_Media_Mode enter, Thu Dec  3 16:12:54 2020
2020-12-03 16:12:54.951212+0100: NOTICE: kIOFBNotifyOnlineChange 0x0 fb[ 0 ] -> online, Thu Dec  3 16:12:54 2020
2020-12-03 16:12:54.951236+0100: NOTICE: Update display map to fb[ 0 ] - online
2020-12-03 16:12:55.797035+0100: LinkUpdate: 3.0 event: Change [2]
2020-12-03 16:12:55.797099+0100: NOTICE: accepted No_Media_Mode exit, Thu Dec  3 16:12:55 2020
2020-12-03 16:12:55.797219+0100: NOTICE: doChange: addr 1.0 [7]
2020-12-03 16:12:55.797287+0100: NOTICE: doChange: addr 2.0 [7]
2020-12-03 16:12:55.797585+0100: NOTICE: doChange: addr 3.0 [7]
2020-12-03 16:12:55.992184+0100: NOTICE: Populated addr 3.0 38a3:2dda UUID 0 order 0:0 tx 2:2 dsp 1 WL 0 MS 0 edid 256 undef 0 DSC 0
2020-12-03 16:12:55.992334+0100: NOTICE: doChange: addr 4.0 [7]
2020-12-03 16:12:55.992439+0100: NOTICE: doChange: addr 5.0 [7]
2020-12-03 16:12:56.214812+0100: NOTICE: Do online device addr 3.0 processCount 1
2020-12-03 16:12:56.216199+0100: NOTICE: Sync LinkTrain Port: 3: SST, 4 lanes @ HBR2 FEC disabled
2020-12-03 16:12:56.296921+0100: NOTICE: FB AGDC state FB[1] - ON
2020-12-03 16:12:56.296981+0100: NOTICE: inject FB[1] change
2020-12-03 16:12:56.297014+0100: NOTICE: Do online device addr 3.0 id 38a3:2dda UUID 0 order 0:0 edid 256 undef 0 - completed
2020-12-03 16:12:56.297054+0100: NOTICE: Addr: 3.0 event: Change [2] source: 3
2020-12-03 16:12:56.297072+0100: NOTICE: doChange: addr 3.0 [3]
2020-12-03 16:12:57.387406+0100: NOTICE: kIOFBNotifyOnlineChange 0x1 fb[ 1 ] -> online, Thu Dec  3 16:12:57 2020
2020-12-03 16:12:57.387458+0100: NOTICE: Update display map to fb[ 1 ] - online
2020-12-03 16:12:57.388980+0100: NOTICE: Port non-scanned FB[ 1 ] link is good ...
2020-12-03 16:12:57.591740+0100: NOTICE: Populated addr 3.0 38a3:2dda UUID 0 order 0:0 tx 2:2 dsp 1 WL 0 MS 0 edid 256 undef 0 DSC 0
2020-12-03 16:12:57.591769+0100: NOTICE: Device addr 3.0 is same ...
2020-12-03 16:12:57.591834+0100: NOTICE: Addr: 3.0 event: Change [2] source: 0
2020-12-03 16:12:57.591848+0100: NOTICE: doChange: addr 3.0 [0]
2020-12-03 16:12:57.593274+0100: NOTICE: Port non-scanned FB[ 1 ] link is good ...
2020-12-03 16:12:57.842227+0100: NOTICE: Populated addr 3.0 38a3:2dda UUID 0 order 0:0 tx 2:2 dsp 1 WL 0 MS 0 edid 256 undef 0 DSC 0
2020-12-03 16:12:57.842266+0100: NOTICE: Device addr 3.0 is same ...
2020-12-03 16:12:57.842333+0100: NOTICE: doChange: addr 1.0 [7]
2020-12-03 16:12:57.842349+0100: NOTICE: doChange: addr 2.0 [7]
2020-12-03 16:12:57.842384+0100: NOTICE: doChange: addr 3.0 [7]
2020-12-03 16:12:57.843812+0100: NOTICE: Port non-scanned FB[ 1 ] link is good ...
2020-12-03 16:12:58.091877+0100: NOTICE: Populated addr 3.0 38a3:2dda UUID 0 order 0:0 tx 2:2 dsp 1 WL 0 MS 0 edid 256 undef 0 DSC 0
2020-12-03 16:12:58.091913+0100: NOTICE: Device addr 3.0 is same ...
2020-12-03 16:12:58.091975+0100: NOTICE: doChange: addr 4.0 [7]
2020-12-03 16:12:58.092016+0100: NOTICE: doChange: addr 5.0 [7]

Youtube video showing how it looks when connected:

 

[Carrotcruncher]

Believe it or not this issue in various similar forms has been around since late 2019 and Apple still haven't fixed it, obviously with the recent code changes the issues are becoming more pronounced, now its come back to bite em in the butt because the didn't deem it crucial at the time ! Well done Craig ?

 

[Diwad]

Last hope is the original thunderbolt 3 cable. I'm gonna test it on Monday.

 

[tunecatcher]

Something similar here. The external display goes black for a few seconds every now and then. MBA M1, USB-C-to-DisplayPort.

 

[Diwad]

Tested original thunderbolt 3 cable. Same story. I'm pissed as hell.

 

[bobthesponge]

Something similar here. The external display goes black for a few seconds every now and then. MBA M1, USB-C-to-DisplayPort.

I have the same problem with a MBP M1, USB-C to USB-C. External display goes black for a few seconds every now and then, as if the cable disconnected. Happens sporadically several times a day. Happens on both ports. Tried changing cable. Tried resetting the SMC. No luck so far.

 

[Diwad]

I've reached nec rep and after few days they fount the cause. Will release firmware update. Also said its Apple's fault??‍♂️

 

[antwormcity]

Found this post while my M1 Air is on order and I am considering buying the same NEC EA271-U 4K UHD display. Was NEC firmware update released and/or able to resolve the issue for you?

Did you try with other 4K monitors perhaps LG or others?

EIZO has a warning for users as the colorspaces don't conform with thei Flexscan displays for the new M1 based Macs. Such a mess here and there looking for monitor options.

Thanks for any pointers on the NEC!

 

[beeline09]

Pardon my English, I use a translator...
I found a solution. I have a nec ea271u monitor and a Macbookpro 2021, and when connected via Type-C, the monitor constantly rebooted and did not show anything. As it turned out, the problem is that Apple updated something related to power delivery in new macbooks and now old monitors that did not receive updates for Type C could not agree on communication lines. But I accidentally decided to go into the engineering menu (careful!!! voids the warranty!!! I am not responsible for your actions!!!) and disable the parameter shown in the picture and... miracle!!! The monitor began to show a picture!

Keep in mind that you can get into the engineering menu only if a source is connected and a picture is displayed. I used the HDMI port as a temporary solution.

To get into the engineering menu, you need to do the following steps:
- Press the menu button
- Go to the information page (at the end on the right)
- Hold down the input and split screen buttons together, after which a warning will appear about voiding the warranty if you continue
- Press the input button and get into the engineering menu

 

[Diwad]

Interesting. So it seems it's not needed to update the firmware by service center. You found some downsides @beeline09 ?

 

[beeline09]

Interesting. So it seems it's not needed to update the firmware by service center. You found some downsides @beeline09 ?

I think it makes no sense to overpay for going to a service center))
It's been working great for me for a few hours now. By the way, the monitor wakes up faster through Type-C than through a Type-C to HDMI adapter. USB works great. I switched it to USB 2.0 so I have 4K60.

 

[Diwad]

Did you change any other sertings? I get No signal message every time after changing the setting. Tried multiple cables.

 

[beeline09]

Did you change any other sertings? I get No signal message every time after changing the setting. Tried multiple cables.

No. Recommend to factory reset after change this setting.
I'm use Belkin Type-C cabel.With any other types of cables that I have at home, the monitor did not want to work, except for this one. And further. At the time this option was disabled in the service menu, the macbook was already connected to the monitor at the same time Type-C and through the adapter HDMI.

 

[Diwad]

I tried 3 cables including Apple thunderbolt 3. Can you specify which exact Belkin one you’re using? Thanks in advance @beeline09

Edit:
After playing with settings usbc works but it doesn’t matter what option I have set in SSC menu. Does it work for you when the lid is closed? For me the image is like frozen but I can see mouse pointer.

 

[beeline09]

I tried 3 cables including Apple thunderbolt 3. Can you specify which exact Belkin one you’re using? Thanks in advance @beeline09

Thunderbolt cable does supported for this monitor. Need a Type-C with video support 4K and at least usb 3.1 gen 2. It's something similar to this: Belkin

 

[Diwad]

I’m not sure how this could help while I’m using 10-40Gb/s cables but I’ll try 🧐

 

[beeline09]

I’m not sure how this could help while

I'm use Belkin USB-C 10 Gbit. Not Thunderbolt. Did you succeed?