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Mobius Pizza
6 Indium

U2711 power save mode continuous wake up loop (Display Port)

Hi

I have this problem of my U2711 monitor after requested by Windows to go to power save mode, but only wake up itself momentarily after power button sucessfully turn orange. This will then repeat in an endless cycle, waking up and going to sleep. I have only observed this behavior using Display Port. This is observed on an ATI HD6950 with stock CD driver and Catalyst 10.12a.

This problem is extremely annoying as the display turns on and off, and the card reader will prompt a 'device attached' and 'device detached' Windows sound continuously. The only way is to disable auto monitor off in windows, this is nto satisfactory as I would like the power saving given number of monitors I have.

Maybe this has something to do with it turning off the card reader power. If so that'd be unfortunate as there will be no way to fix it. This is also a major problem of the U2711. If you have file transfers occuring with a SD card for example, and the display goes off, your transfer will then fail. It should never power off the USB card reader, given that the USB power provided by the case should be sufficient to power the device.

I have also had instances that the display won't recover from sleep. Not sure if this is due to the graphics card or the monitor.

Thanks for any insights

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7 Replies
Moderator
Moderator

Re: U2711 power save mode continuous wake up loop (Display Port)

The monitor is passive meaning that it only receives the DP signal. The video card has to constantly transmit a signal for the monitor to sync it. When the OS goes into PowerSave Mode and you then wake it up, the video card must resync itself to the monitor. I don't know why it is not. Next time you wake it up, disconnect the DP cable from the bottom of the monitor and then reconnect it. Does the monitor then wake up?



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Mobius Pizza
6 Indium

Re: U2711 power save mode continuous wake up loop (Display Port)

Thanks for the reply. After updating to Catalyst 11.1a driver, the symptoms changed.

Instead of a constant sleep wake cycle, it nows try to enter sleep, power button turns orange, turns blue again, but the screen stays black. The same happens to my other monitor.

By the looks of it, since same behavior is observed on my other monitor, it looks like AMD's having problematic drivers.

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pnelson010
1 Copper

Re: U2711 power save mode continuous wake up loop (Display Port)

I'm having a similar problem with my E197FP.  It won't come out of power save mode.  Screen is black and therefore, my whole system is non-functioning.  Is there a solution?

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TomaszTG
1 Copper

Re: U2711 power save mode continuous wake up loop (Display Port)

Hi

I've got similar problem with U2711. There is actually no power save mode issue, however, when I switch my PC to sleep mode (Win7, 5870) and turn off monitor and switch PC on, also monitor then, the U2711 start to run, but it stop to respond. The Power LED is blue and that is all ! I have to manually unplug the monitor from power and connect again. Then monitor wake up ! This is really annoying.

I am very happy of Dell service, since today I got a replacement monitor from Dell. But you can believe me, how I was surprised when I saw the same issue. Interesting, it happen on on DP connection again.

I have also tried different CCC from ATI, no differences 😞 Will that be a general issue in ATI graph cards ? Should I go for nVidia ? 🙂

Thanks a lot for helping me to find out a direction.

Take care

Tomasz

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TomaszTG
1 Copper

Re: U2711 power save mode continuous wake up loop (Display Port)

It seems, that only solution right now is not to power off monitor. OK, I have to pay the 3Watt taken in stand by mode by monitor, but much better then unplagging him every second time when starting PC !

 

Phillennium
1 Copper

Re: U2711 power save mode continuous wake up loop (Display Port)

I have the same issue on my U2711 connected to a Latitue E6400 using DP.

It appears to be happening to the U3011 as well.

Is there an official word on this from Dell?

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TomaszTG
1 Copper

Re: U2711 power save mode continuous wake up loop (Display Port)

I do not see any news from Dell. The only thing that surprised me in a nice way, was that I have received replacement monitor. Unfortunatelly, with the same issue 😉 Bad luck. Right now, I turn monitor to stand by, then it does respond when I turn on PC 🙂 ! This is sorry !

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