SE2717H, no HDMI signal

I have SE2717H monitor that has been working two years. It stopped recognizing HDMI signals from any computer devices I have, and I confirmed that these devices works fine with other monitors through HDMI.

I tried factory resets in two ways;

One was pressing power button for 10 or 30 seconds while all the cables are unplugged, but this didn't work.

I looked for reset menu from OSD, but I couldn't find this option, because my OSD only displays input source selecting option. there was no such thing like "others". 

So my conclusion is this could be due to defect A/D board. It could have been affected by some kind of power surge. What do you think is the problem? Do you think I can fix it? Or, do you think I should bring it to the service center?

Thanks!