I ordered 2 of these. The first came defective, several keys did not light up, and one key was not attached at all. Additionally, when plugged in, the left CTRL key would not respond. The second was also defective. This time all the lights worked, but when I plugged it in, it would constantly send a series of 1s, 0s, and periods for about 5 minutes. After that time, the several keys did not work at all, including the left CTRL key. I tried both keyboards in several different computers, each had the same issue. Perhaps I was unlucky in receiving two defective products, or perhaps the refurb quality is poor.