You might remember in a previous thread I bought a display from someone who claimed to not have a power adapter. So I had to order one from eBay. Received it in the mail this morning. Plugged it in and it worked fine for roughly an hour. I go to lunch for 20 min. When I return, the display is off. Nothing has changed. Everything still plugged in. No power. Is the 90W not right for this display? Anything else about it that would potentially short it out?