Hello. I received a Dell U3011 as a hand me down, so I do not have any original purchase information. It is surely out of warranty by now. I cannot use it because: when I plug it in and turn it on, it flashes the "No DisplayPort Cable" dialog, regardless of whether I put things into its other inputs. And when I try to use the buttons on the side to change the input, those buttons do not seem to register. Only one of them (I think?) even lights up, and none of them cause any result on the screen. All of the diagnostics that posts here say to try do not work.

As a side note, I think the power button itself is somewhat broken: I do not seem to be able to turn the monitor off, regardless of how long I hold it. I still hear a click when I use it, and I need to press it to turn the monitor on after being plugged out, but otherwise I cannot turn it off again.

When I plug in a computer, the computer does recognize the device. I tried using a DDC/CI software (since it appears that this monitor is too old for the Dell Display Manager software) to remotely change the input, but that option was not available. My understanding is that DDC/CI needs to be enabled by the monitor. But this requires use of the buttons that are broken!

But otherwise the screen seems completely fine, and since multiple computers of mine recognize the device I think the logic is okay. So it is frustrating to be unable to operate the monitor. Is there some privilege elevation software that one can use to control the input it recognizes?

And is it worth it for me to buy a DisplayPort cable so that I can see if it actually receives input at all? I do not think I own any; all I have are HDMI and VGA cables (and perhaps a DVI adapter).