I recently purchased a U2415 monitor and I'm using it with a Linux machine. The monitor is really nice and there is only one issue I have with it: After the computer goes inactive and the video card stops sending a video signal the monitor should switch to standby automatically. What happens, however, is that there is an OSD message box telling me that the monitor will switch to standby in 5 minutes and a progress bar showing the remaining time. I would like to switch off this delay, however I don't seem to find any settings for it in the OSD menu. I have been advised to use the Dell Display Manager, however it is designed for Windows only and, installed through Wine, doesn't find a display driver. Installing the display driver, however, fails because the installer doesn't recognize that a Dell monitor is connected.
My questions now are: Is there a way to change this setting without using the Display Manger? If not, is it possible to change the setting using a Windows machine and will this setting be preserved if connected to the Linux machine again? In other words, is this setting saved in the monitor itself or in the computer it is connected to?
Thanks in advance,
I've had some similar problems (not exactly the same model). I found in one case it was the HDMI cable that I was using - using a new cable allowed the monitor to sleep. Also found similar things when using DVI, but it was OK using HDMI or DisplayPort.
It's not a setting in Display Manager. It's a signal that your OS should send to the monitor, depending on power options.
So I tried and it looks like it is actually a monitor issue. If I send the off/suspend/standby signal (doesn't matter which one) via DPMS the monitors turns black for a moment but switches on again after an instant with the message box mentioned above.
Bummer. Could also be your graphics card. Actually I'm pretty clueless, but thought you'd prefer a clueless reply to no reply! Maybe someone who knows their stuff will chime in! What's your graphics card and how are you connecting?
You're right, any reply is better than no reply. 🙂 The graphics card is actually an APU, AMD A4-3400 connected via HDMI. But I can test on a different machine to make sure that the graphics card is not the problem.
I realized that I have no other screens I could connect via HDMI. If I connect another screen via DVI switching to standby works fine. So it is either a monitor or an HDMI issue...
I also have a standby issue with my Dell U2415. I'm using Windows 8 and mDP connector. I wrote a post just now but it's waiting for review. Basically, when Windows does a "turn off display" my U2415 goes into a "dark grey" color. That might be what you want. For me, I actually want the monitor in "power save mode" as you are getting (after the 5 minute wait) because power save mode is completely black (instead of dark grey which you can see in a dark room).
I think, your issue is actually software related since the monitor doesn't go to standby (stays on and only gets a black screen overlay with backlight still on). In my case it kind of goes to standby for a short moment but wakes up again with the bloody waiting message...