2408WFP Solid green light, no image, can't turn off

I purchased my Dell 2408WFP from Dell in September 2009. It had been working flawlessly until a couple days ago. Now when I plug in the power cable, and only the power cable, the green power light turns on immediately even though I haven't pressed the power button, and it doesn't turn off, blink, or turn orange. Pressing the power button or holding the power button doesn't make a difference. The light always stays on.

I tried unplugging the monitor for several minutes, holding down the power button for 30 seconds, then plugging it in again. I also swapped out the power cable.

The problem started after I moved the monitor from a custom monitor stand back to the one it was sold with, which involved unplugging all the cables and moving it around a little, but I didn't think it suffered any trauma. It hasn't worked since then.

For the past few months I've been using it with a USB-C hub and a MacBook. The hub splits the USB-C output from the MacBook to USB and HDMI, which were both plugged in to the monitor. They were working fine before then. Is there a chance that somehow damaged the monitor?