Best seller & Best product!! Mate, you wouldn't even believe it, I have an Asus R752L, the same as Asus X751L in terms of hardware, bought it as second-hand, but it looks like new, only a few of the keys didn't works so well after about 30 minutes from turned it on, those were the: R + U + T, when I bought an 8 gb memory & a WiFi 5 G card and wanted to replaced them, I opened the Asus, after placing these I pressed a bit hard on the back of the keys those were not working after a 30 minutes, and closed it.. the keyboard now works perfectly so no more defective keys, maybe the previous owner has not properly secured the K-board cables as well.. see wifi cables on the tape? all in all, I now have a new keyboard as a reserve.. hurray! This seller is exceptionally friendly & nice guy too.. wish him all the Best!!