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M1 Air ghosting, flickering with external display

aednichols

macrumors 6502
Original poster
Jun 9, 2010
346
246
My M1 MacBook Air has a serious problem with external displays. Pinging the brains here in case there are any ideas more convenient than sending back to Apple.

Connecting directly via a known-good USB-C to DisplayPort cable, my Dell U2713HM (1) flickers, (2) shows vertical lines, and (3) mixes together previously-displayed frames with what should actually be on screen.

That last issue is the easiest to photograph. If I look at Discord and then lock my machine, a ghostly vestige of it shows through on the lock screen. This happens even if I quit Discord entirely, so it's not some sort of transparency effect:

IMG_3331.jpeg
IMG_3330.jpeg
 

Sanpete

macrumors 68030
Nov 17, 2016
2,833
1,257
Utah
Sure looks like a physical problem. I get ghosting like that and flickering on my built-in screen from water damage to the screen area. If you're sure it's not your cable, looks like you need to return it.
 
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23b

macrumors newbie
Nov 26, 2020
5
1
My monitor (usb-c, 4K) switches off for like 3 seconds every now and again (every hour?). I use sidecar and macbook air at the same time. Anybody else encountered this?

Edit: Monitor actually goes in standby, it's possible to abort the standby which just makes it go dark for a short time.
 
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TomOSeven

macrumors 6502
Jul 4, 2017
460
488
My external monitor is super blurry at 1920*1200 pixels and everything's tiny.
I can reduce the resolution to "scaled" for 1440*900, but then things are even more blurry.

On Windows, I can just increase the scaling factor to like 125% and everything remains crisp.

Is there a way to fix this? Otherwise I'll have to return the Macbook.
 
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aednichols

macrumors 6502
Original poster
Jun 9, 2010
346
246
My monitor (usb-c, 4K) switches off for like 3 seconds every now and again (every hour?). I use sidecar and macbook air at the same time. Anybody else encountered this?
Is it the LG Ultrafine?
 
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aednichols

macrumors 6502
Original poster
Jun 9, 2010
346
246
Sure looks like a physical problem. I get ghosting like that and flickering on my built-in screen from water damage to the screen area. If you're sure it's not your cable, looks like you need to return it.
Can you post a
My external monitor is super blurry at 1920*1200 pixels and everything's tiny.
I can reduce the resolution to "scaled" for 1440*900, but then things are even more blurry.

On Windows, I can just increase the scaling factor to like 125% and everything remains crisp.

Is there a way to fix this? Otherwise I'll have to return the Macbook.
Can you post a photo? Please, also as many specs of the display as you know.
 
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david9992

macrumors newbie
Nov 14, 2020
10
6
My M1 MacBook Air has a serious problem with external displays. Pinging the brains here in case there are any ideas more convenient than sending back to Apple.

Connecting directly via a known-good USB-C to DisplayPort cable, my Dell U2713HM (1) flickers, (2) shows vertical lines, and (3) mixes together previously-displayed frames with what should actually be on screen.

That last issue is the easiest to photograph. If I look at Discord and then lock my machine, a ghostly vestige of it shows through on the lock screen. This happens even if I quit Discord entirely, so it's not some sort of transparency effect:

View attachment 1679809 View attachment 1679808
Exactly same issue here, MBP2020 M1, shows vertical lines on my PHILIPS 288B6LJRNB 4K display.
 
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burni

macrumors newbie
May 10, 2020
15
3
I've got a Del U2712 (I think it's a 12, could me a 13) connected to my M1 MBP via USB-C to DP and a couple of times a day it starts to flicker and get vertical lines. I ordered a different USB-C to DP cable to test and it's the same.

The other issue is that if I open a Apache log file in Console I get a high pitched whine noise. It seems to be coming from the monitor. It's only when there's a full screen of text. Normal coding where there's lots of blank space doesn't make it whine. Odd.

I need to order a USB-C to HDMI so I can check it if does it with my wife's 24" Dell monitor.

I'm guessing the only thing I can do is contact Apple support?
 
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david9992

macrumors newbie
Nov 14, 2020
10
6
I've got a Del U2712 (I think it's a 12, could me a 13) connected to my M1 MBP via USB-C to DP and a couple of times a day it starts to flicker and get vertical lines. I ordered a different USB-C to DP cable to test and it's the same.

The other issue is that if I open a Apache log file in Console I get a high pitched whine noise. It seems to be coming from the monitor. It's only when there's a full screen of text. Normal coding where there's lots of blank space doesn't make it whine. Odd.

I need to order a USB-C to HDMI so I can check it if does it with my wife's 24" Dell monitor.

I'm guessing the only thing I can do is contact Apple support?
Tell us if USB-C -> HDMI adapter help. ;)
 
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burni

macrumors newbie
May 10, 2020
15
3
I don't understand? I said it's connected via USB-C to DP. I've tried two different USB-C to DP cables as mentioned.

I've ordered a USB-C to HDMI cable to test, but don't have it yet.
 
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burni

macrumors newbie
May 10, 2020
15
3
I don't understand? I said it's connected via USB-C to DP. I've tried two different USB-C to DP cables as mentioned.

I've ordered a USB-C to HDMI cable to test it on another monitor in the house (which doesn't have DP), but don't have it yet.

EDIT: Oops hit reply instead of edit...)
 
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david9992

macrumors newbie
Nov 14, 2020
10
6
I don't understand? I said it's connected via USB-C to DP. I've tried two different USB-C to DP cables as mentioned.

I've ordered a USB-C to HDMI cable to test, but don't have it yet.
Yeah, I mean after your test, tell us if it works. I'll buy one too. 🤣
 
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SHates

macrumors newbie
Jun 13, 2012
29
3
I'm getting the same issue on my M1 Mini when running 4k via HDMI. Works fine with USB-C to DisplayPort.

What's even more strange is that it only happens if I create a new blank tab in Firefox, or type in the address bar. Apart from that, it's fine.
 
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aednichols

macrumors 6502
Original poster
Jun 9, 2010
346
246
After some more debugging, it looks like a display problem after all: the problem now happens with my Intel MBP from work also.
 
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aednichols

macrumors 6502
Original poster
Jun 9, 2010
346
246
I've got a Del U2712 (I think it's a 12, could me a 13) connected to my M1 MBP via USB-C to DP and a couple of times a day it starts to flicker and get vertical lines. I ordered a different USB-C to DP cable to test and it's the same.

The other issue is that if I open a Apache log file in Console I get a high pitched whine noise. It seems to be coming from the monitor. It's only when there's a full screen of text. Normal coding where there's lots of blank space doesn't make it whine. Odd.

I need to order a USB-C to HDMI so I can check it if does it with my wife's 24" Dell monitor.

I'm guessing the only thing I can do is contact Apple support?
Are you sure the whine is new with the M1?

I am also a programmer and my U2713HM Has whiled for years with a large log on screen.

Maybe you're paying closer attention with the new machine.
 
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Mgracia

macrumors newbie
Nov 27, 2020
1
0
I am experiencing similar flickering problem with my M1 MacBook Air, when connecting my LG 27GL83A-B with USB-C to DisplayPort cable, the M1 seems to detect it and set the refresh rate to 144hz, after some time with this configuration the flickering starts, I Switch to 120hz and it remains stable with no flickering but if I go back to 144 it gets even crazier than before. With the same exact same cable on my MacBook Pro 2018 intel model my monitor works perfectly.
 
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aednichols

macrumors 6502
Original poster
Jun 9, 2010
346
246
I would strongly encourage folks to post photos or videos if possible. The problem I originally posted about has been conclusively ruled out as a display issue, and I suspect what's in my photos looks pretty distinct from what you all are seeing.
 
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burni

macrumors newbie
May 10, 2020
15
3
Are you sure the whine is new with the M1?

I am also a programmer and my U2713HM Has whiled for years with a large log on screen.

Maybe you're paying closer attention with the new machine.
It’s possible but don’t recall it before. Maybe the fan noise on my old MBP was drowning it out lol!

Will check on the Dell 24” screen I have, when I get the cable. Might just be coincidental timing and the monitor is worn out. The 27” is nearly 8 years old now but the 24” is only 4-5 years old.
 
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burni

macrumors newbie
May 10, 2020
15
3
DVI to USB-C cable preliminary findings: 27” still makes whining noise with log file. Doesn’t occur on 24”.

Haven’t been able to trigger the flickering yet but it’s random. I’ll work via the DVI cable for the next few days on the 27” and see if it occurs.
 
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