Dell U3419W connected via USB C keeps scanning for signal when MacBook is sleeping

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Level 1

16 points

Dell U3419W connected via USB C keeps scanning for signal when MacBook is sleeping

I use a Dell U3419W with my 2016 MacBook Pro, connected via USB C. When my Mac is closed and sleeping, the monitor keeps looking for a signal. The screen comes on quickly and I hear the sound you hear when you connect your Mac to power.

I found a post in the Dell support forum describing this issue, but Dell doesn't seem to feel any responsibility for their Mac users and sends us to Apple instead. Anyone here has any suggestions?

https://www.dell.com/community/Monitors/U3419W-scanning-for-signal-when-Apple-is-asleep/td-p/7254570

Also, I noticed I can't control the monitor's speaker volume using the volume keys on my Magic Keyboard. Again Dell points at Apple.

https://www.dell.com/community/Monitors/U3419W-MacBook-no-volume-control-with-keyboard/td-p/7316633

MacBook Pro with Touch Bar

Posted on Jul 11, 2019 6:20 AM

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Answer 1

Dec 25, 2019 7:46 PM in response to noafe

That didn't work for me.

I've tried different combinations of the options:

In MacOSCatalina: "Prevent computer from sleeping automatically..." (On/Off), Power Nap disabled
In Monitor: "Input Source" (Autoselect), USB-Charging (On/Off During Power Off).

No combination works for me - MacBook Pro (15-inch, 2017) wakes up right after I turn it off.

So there are three threads discussing the same issue now:

https://www.dell.com/community/forums/replypage/board-id/Monitors-Forum-f3529/message-id/122971

https://www.dell.com/community/Monitors/U3419W-scanning-for-signal-when-Apple-is-asleep/td-p/7254570

https://discussions.apple.com/thread/250477993?answerId=251481545022#251481545022

Should be a fix in the Monitor firmware.

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Answer 2

JordyP84 Author

Level 1

16 points

Sep 1, 2019 8:42 AM in response to a_sudz

I started turning off my display when my MacBook goes to sleep, but I found out it doesn’t charge when it’s turned off. I actually ran out of battery one time when installing a software update. The display didn’t charge my laptop during the installation process.

I still don’t understand how this could be an issue with my Mac and not the display. Dell says it works with Windows, but I find that hard to believe with so many different manufacturers.

If it’s on Apple to fix, could be this be a firmware update?

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Answer 3

dvdswrd

Level 1

4 points

Oct 23, 2019 4:53 PM in response to JordyP84

So I came here with the exact same problem. Brand new Dell U3419W out of the box and I'm connected to two machines:

MacBook Pro > USB-C
Mac Mini > Displayport

I also have USB-C charging set to "ON" when the display is off. But I don't think that setting makes a difference because that's just saying your computer will charge when the monitor is turned off—Has nothing to do with this issue.

Issue: While on my Mac Mini (Displayport input), I was getting USB-C "unplugged" / "plugged" notices from the Dell monitor, about every 30 secs to a minute. The MacBook Pro was triggering this. Checked the cable and everything seemed to be fine.

I've solved the issue by going to the MacBook Pro and turning off Energy Saver features for Power Adapter mode. It's up to you what settings you want for Battery too:

[ENABLE] Prevent computer from sleeping automatically when the display is off

I think this is the key setting. Sleeping any macOS machine is BAD if you want connectivity to certain devices to stay persistent.

[Disable] Put hard disks to sleep when possible

Turn this off. It's probably not relevant to this display issue, but this can also cause connectivity issues with devices that use your disk (e.g. If you're a video editor)

[Disable] Power Nap

This should always be off, regardless of this display issue. It's a terrible feature that causes a lot of problems with apps and device connectivity. I'd guess that this is what was causing the problem... Every time you got the spotty connection warning, I bet the computer was doing it's periodic checks for email or whatnot, turning itself on briefly, triggering the monitor. I would guess that this also affects the "Auto" input switching—If you have that turned on, Power Nap would be switching your inputs when you don't want it to.

Annoyances, but I think they're solvable :) Hope this helps!

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Answer 4

Jul 30, 2019 8:23 AM in response to JordyP84

When the display is powered on, but does not receive a signal, it is predictable behavior that it would scan for a signal. That message is coming from the microprocessor in the display, not from your Mac.

I do not understand how this is a defect, can you help me understand? what did you want the display to do?

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Answer 5

Jul 30, 2019 8:55 AM in response to Grant Bennet-Alder

Any other displays I had with USB ports were searching for a signal, but not waking up the computer while still powering the device. I think the problem is that, when the monitor goes in sleep mode, the USB hub is powered down, so when it wake up to search for a signal, it power up, giving the mac the impression it was plugged into a power source, and wake it up.

I should have an option in the personalize menu with the latest firmware to let the USB power on while the screen is turned off, but I don't have it even if I have the latest version of the firmware...

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Answer 6

JordyP84 Author

Level 1

16 points

Jul 30, 2019 9:00 AM in response to Grant Bennet-Alder

It's not su much the message that's the problem it's the sound that comes out of my MacBook when the monitor starts charging it. When there's no signal, the monitor is not sending power continuously so every few minutes I hear the sound you normally only hear one time when you plug in power. That's what gets annoying.

Ideally the display also just turns black and stops displaying a message that it's looking for signal (eventually it does go black), but the charging sound issue remains.

LG's USB C monitor doesn't have any of these issues.

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Answer 7

JordyP84 Author

Level 1

16 points

Sep 1, 2019 9:19 AM in response to Grant Bennet-Alder

That somewhat defeats the purpose of getting a USB C monitor, but I’ll definitely give it a try. Most often my personal MacBook is there plugged in anyway. I switch to my work MacBook once a week when working from home. Sometimes my wife plugs in hers.

For now I’d be happy with the sounds stopping. So if an extra power cable solves that problem that’s an acceptable temporary fix.

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Answer 8

JordyP84 Author

Level 1

16 points

Sep 1, 2019 7:23 PM in response to Grant Bennet-Alder

So I used a separate power adapter to charge my Mac while connected to the monitor. It stops the charging sound, but I did notice my monitor wakes up once in a while and displays a message saying it's looking for signal. I wish it would just stay black until I wake up my MacBook.

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Answer 9

Sep 1, 2019 9:34 PM in response to JordyP84

The sound is coming from the computer when you plug the power in. Since you have a power source connected to it, it stopped the sound when its waken up. I wish we could found a solution, it's making all the extra functions of this monitor nearly useless to me!

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Answer 10

JordyP84 Author

Level 1

16 points

Sep 2, 2019 5:41 AM in response to Frédéric Harper

This also shows there’s still an opportunity for Apple to add value in the monitor space. I wish there was a USB-C successor to the Cinema Display. I know they sell the LG monitors but I prefer a larger and ultra wide screen.

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Answer 11

JordyP84 Author

Level 1

16 points

Sep 6, 2019 11:08 AM in response to Frédéric Harper

It looks like there’s a new firmware. I didn’t had a chance to try it myself but based on the description this fixed the charging problem. https://www.dell.com/support/home/us/en/04/drivers/driversdetails?driverid=82y9g&oscode=mac1&productcode=dell-u3419w-monitor

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Answer 12

Sep 6, 2019 2:54 PM in response to JordyP84

It is a little difficult to get it to download. I had to go back to the downloads page, and it was still cranky about actually downloading. Once you get it downloaded, the .pkg is not tagged with a developer certificate, so you have to use the (Open-anyway) button in System Preferences > Security&Privacy

Once you get that opened, it launches its Installer. Once installed, it launches its Firmware-Updater and wants to do the update right then. Caution, says it takes a quarter hour and can NOT be interrupted or you will damage the display.

--------

It certainly is duplicitous of them to disclaim all support for Mac ANYTHING, then issue a Mac-specific display-firmware updater that is a Mac Application.

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Answer 13

JordyP84 Author

Level 1

16 points

Sep 8, 2019 5:25 AM in response to Grant Bennet-Alder

So the new firmware allows the monitor to charge via USB-C when it's turned off, but unfortunately my MacBook keeps making the 'ding'-sound once regularly, as if it's being connected to a new power source. It appears the monitor doesn't provide a continuous charge.

I'm glad I no longer have to see the monitor light up and show a message that it's looking for signal, but it only solves half of the problem.

I hope this update shows Dell is listening to our complaints and takes their Mac customers more seriously and that we can expect another update soon that fixes the other issues.

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Answer 14

Sep 12, 2019 5:24 PM in response to JordyP84

The updated firmware for the Dell U3419W offers the option to keep the USB-C power on even when the monitor is powered off. the firmware update tool is dated August 19.

Update the firmware on the monitor (follow instructions)

Access the on screen menu, go to Personalize, USB-C Charging to enable

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Answer 15

Sep 13, 2019 11:17 PM in response to SteveR514

Does the enabling of USB-C charging mean the power stays continuous when the monitor is off and stop the waking noise on the laptop? I'm running a MBPro 2019 and really want to get a USB-C monitor however its too much if its still not right ....

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