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August 1st, 2017 21:00

U2717D Scanning for signal when laptop screen in power save

Using a U2717D connected to a Latitude E7470 via mini-DisplayPort (laptop side) to DisplayPort (monitor side).  I have the system configured to extend across both the internal LCD and external monitor.  Laptop is running Windows 10 64-bit.

Whenever the laptop puts the screen into sleep mode, the U2717D goes into power save mode, but then wakes up every minute or so with a message "Scanning for signal" on the screen.  This behavior completely defeats the purpose of power save mode.  If I turn off the monitor, the USB goes away and Windows reverts all open programs to the laptop screen only (as it now sees the monitor as having been removed), so this is not an acceptable solution.

What is the solution to this?  How can I get the screen to stay in power save mode until the laptop revives it without the constant scanning for signal?

December 9th, 2017 05:00

I think I have found a solution. I was going to try changing some settings on the display and in Windows this morning, but it seems the first try was already successful. I set the Monitor Sleep option in the display's OSD to "Never". I left the Windows power settings unchanged (let monitor go to sleep after one or two minutes), but the issue is gone. The monitor goes to sleep as it should and only turns on again when I e.g. move the mouse or press a key on the keyboard.

This does raise the question for me what that Monitor Sleep option in the display's OSD is for. What does that do? Can you explain?

Community Manager

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August 2nd, 2017 08:00

It should not be doing this. The laptop has to be sending some signal activating the monitor. See page 47. While testing, be sure that the U2717D USB 3.0 upstream cable is NOT connected to the laptop. Just to remove it from the troubleshooting.

Can you replicate the issue when testing a mDP to mDP cable?
Latitude E7470 mDP out port --> mDP to mDP cable --> U2717D mDP in port

What happens when you put the laptop into Hibernate rather than Sleep?

5 Posts

August 2nd, 2017 14:00

To be clear, the laptop is not sleeping or hibernating, it has been idle so the screen is turned off for power save mode.  I don't have an mDP to mDP cable, but have changed to an HDMI cable to see if that makes a difference.

Community Manager

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54.2K Posts

August 3rd, 2017 07:00

"it has been idle so the screen is turned off"

it  = the E7470 or the U2717D?

screen = the E7470 or the U2717D?

5 Posts

August 6th, 2017 19:00

"it" is the laptop.  When the screensaver starts it puts the screens into power-save mode.  Both "screens" are affected (the laptop screen and the U2717D).  I really don't think this is an uncommon setup (laptop connecting to an external monitor and using both the laptop screen and monitor as an extended desktop).    The problem is that the U2717D keeps waking up and scanning for a signal every few minutes.

I have switched to HDMI and it might be better (it also fixed some problems I was having with sound through the monitor), but this is not a good long-term solution as I plan to connect another U2717D via mini-DP to extend across all three monitors (laptop + U2717D + U2717D).  I don't think I can daisy-chain when using HDMI.

Community Manager

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54.2K Posts

August 8th, 2017 07:00

Get an exchange. If the replacement monitor does not have the issue, return the original monitor back to Dell. If the replacement monitor has the SAME issue, I doubt that both monitors are defective. I would return the replacement monitor back to Dell. Then look to the computer, video card, video card ports, video card driver, cabling, or the operating system itself as the possible culprit.

5 Posts

August 22nd, 2017 08:00

I have 2 of these monitors and they both have the same behavior.  There is also a lag in audio when running the Windows audio test.  I don't have either of these issues when using HDMI.  I saw somewhere else that DP is just a big problem in general, so maybe this could be it.

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October 4th, 2017 20:00

Similar problem.

Precision Laptop/E-Port Plus II (PRO2X DPN JKJ9X A02) connected to a U2717D. When Laptop goes into power saving mode. Laptop and U2717D go dark, as expected.  The USB Cable has been disconnected.

About every Minute, U2717D wakes up and displays:

1. "No DP Signal from your device" then "

2. "Entering Power Saving Mode"

3. Wait 'bout a minute and go to 1.

DP to DP cable is being used. I replaced a DP to mDP cable, which exhibited the same behavior.

I don't have HDMI ports on the Dock. Should this Monitor be exchanged for a different module?

Update: A Dell Del ST2210B does not exhibit the above problem. It goes to sleep and stays dark until the Laptop is revived. 

December 6th, 2017 09:00

Just purchased this monitor and have the issue too with the included mDP-DP cable. Seems to me this is an issue of the U2171D, since I did not have it with another monitor I used recently with an mDP-DP cable.

Are there any updates? What can be done about this? Does this issue also occur with desktops?

Community Manager

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54.2K Posts

December 6th, 2017 12:00

monitorview,

I have not seen any updates from the previous users nor did they post their U2717D 20 digit serial number and A0x revision. What is your U2717D 20 digit serial number and A0x revision? Back in May, a user asked about revision A03. That is the latest version reported. If this were a systemic issue with all U2717D, we should be seeing thousands of similar complaints.

* Was the monitor purchased new directly from Dell? Or from a reseller?
* What specific computer model?
* What operating system?
* What specific video card?
* What video out ports are on the video card to test? (VGA/DVI/HDMI/DP/mDP)

Community Manager

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54.2K Posts

December 7th, 2017 13:00

The service tag is confidential. The 20 digit serial number is not confidential. Post the serial number. When connected via HDMI to HDMI cable, what is the resolution and Hz? When connected via the Dell mDP to DP cable, what is the resolution and Hz? Consider purchasing a mDP to mDP cable to test the U2717D mDP in port. You should also update the Intel HD Graphics 520 driver from here. Then retest.

December 7th, 2017 13:00

Hi Chris,

Thanks for your response. I have the A03 revision, production date March this year. I am hesitant to post my serial number online. If you really need it, is there perhaps another way of sending it to you? The thing is that I don't have the issue when using the HDMI-connection. If most people use HDMI instead of displayport, that might explain the limited number of complaints? And perhaps it only has this issue with notebooks? I have not connected the USB cable.

As to your other questions:

- From a reseller

- Lenovo Thinkpad T460

- Windows 10 x64

- Intel HD Graphics 520

- mDP, HDMI (as mentioned, HDMI does not have the issue)

Community Manager

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54.2K Posts

December 9th, 2017 06:00

According to the U2717D User's Guide, the OSD- Display- Monitor Sleep has two options =
Sleep After Timeout: Monitor goes into sleep after timeout
Never: Monitor never goes to sleep

Choosing "Never" must remove the monitor from all PSM command allowing only the operating system to run it. I agree, that seems odd.

5 Posts

December 11th, 2017 07:00

OP here.  This is a great find.  I tried this setting out and it also had the desired effect.  Now when the laptop screen goes to sleep, so do both my monitors (connected via mDP daiy chain), and the monitors stay asleep until I wake up the laptop.

December 11th, 2017 07:00

Thanks. The default option is the first one you mention. But well, it seems to work now. :-)

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