Monitor losing signal randomly, every 2-45 minutes

Question

Level 1

119 points

Monitor losing signal randomly, every 2-45 minutes

For years, my 2014 MacBook Air flawlessly outputted a secondary display to a Dell 27-inch monitor (U2718Q)

I recently switched to a 2019 16-inch MacBook Pro (2.4 GHz 8-Core Intel Core i9, AMD Radeon Pro 5500M 4 GB, Intel UHD Graphics 630 1536 MB). This device is far more powerful, so I expected it to work at least as well. However, when the monitor is connected to this device, the monitor randomly loses signal every few minutes—e.g., every 2 to 45 minutes.

Other potentially relevant factors:

The MacBook Pro clearly thinks that it is still connected to the display even when the display loses signal. For example, system preferences and "About This Mac" still shows the monitor connected and using the AMD Radeon Pro 5500M.
The signal loss occurs on battery and on power adapter.
The signal loss occurs no matter which of the 4 USBC ports that I use.
The timing of the lost signal seems random. I try to time it, but there is virtually no discernible pattern that I can detect.
If I turn on "mirror displays" during a loss of signal, the monitor regains signal and mirrors the MacBook Pro's display.

Troubleshooting steps so far:

Reset the monitor
Receive a replacement monitor from Dell
Restart Macbook Pro
Reset SMC on Macbook Pro
Reset VRAM on Macbook Pro
Fresh install of macOS Catalina (latest version)

Please advise.

Alternatively, does anyone want to buy a nrefurbished Dell U2718Q?

MacBook Pro with Touch Bar

Posted on May 20, 2020 5:47 AM

Reply

Answer 1

rose_10

Community Specialist

May 20, 2020 6:13 PM in response to xser

Hey there, xser,

Thanks for visiting the Apple Support Communities. I understand that you've been having connection issues between your MacBook Pro and Dell display. I'm happy to help!

It looks like you've already done quite a bit of troubleshooting. Since the issue continues, I would suggest following the "Before you begin" steps outlined in Get help with video issues on external displays connected to your Mac - Apple Support.

Then if you still need help, you'll want to get in touch with Apple Support directly. You can do that here: Contact Apple Support.

Have a wonderful day!

Reply

Answer 2

xser Author

Level 1

119 points

May 27, 2020 7:41 AM in response to xser

Update 1: this sometimes happens the moment that I connect or disconnect the USBC power cable to/from the MacBook Pro—from any of the ports.

This makes wonder if causes could be:

A short—I sometimes see tiny sparks from the USBC ports/cables as I plug or unplug power.
A SMC-type issue—e.g., power management is causing a change that interrupts/stops signal to external display.
A graphics card switch issue—e.g., when switching between battery to power adapter, the MacBook might switch the external display's processing from the discrete graphics card to the integrated graphics card. Perhaps this switch causes a momentary loss of signal that is not automatically rebroadcast to the monitor.

Reply

Answer 3

xser Author

Level 1

119 points

Jun 24, 2020 10:51 AM in response to rose_10

I've tried all of the troubleshooting recommended so far, but the issue(s) persist(s).

Also, it looks like the firmware on the Dell monitor can be updated only via Windows.

So if I keep this monitor, I will consider installing Windows on the Mac and trying to update the firmware on the Dull monitor.

Reply

Monitor losing signal randomly, every 2-45 minutes

Similar questions