U2913WM, won't recognize signal

The U2913WM has always been quite finicky to recognize the signal, requiring unplugging, replugging, power cycling. It has suddenly stopped recognizing any signal at all to HDMI or DVI input. I have tried two different and put sources that I know work. Have unplugged, replugged, power cycled, try to manually set input from on-screen menu to no avail. Help?