Hello I have (or I had if it stay dead) a U2312HM that I just upgraded because it started showing ghosting.

So I closed it from the button, disconnected everything from it and took it home where I had an old 19" monitor that is worse than a ghosting old U2312HM. But it never opened again for some reason.

I tried other cables, even returned to my office and tried the original power cable I had it with since yesterday but it refuse to open when I press the power button.

I suspect a power supply failure but it is too old of a monitor to bother with sending it in for repair and then I noticed a 12V input(?) in the back.

What is it? Can it work with external power supply? What do I need to buy?

Thanks!