Today the exact same thing (new camera arrived with the top LCD problem) happened to me
Tomorrow the camera is going back to Amazon UK. After the mirror problem in the K-5 I am very tempted to give up on Pentax but, after some hesitation, I decided to ask for a replacement instead of a refund. Let's see if the replacement arrives without defects.
BTW, I checked without any lens mounted (didn't make a difference). Also it was not related to the battery (which was charged enough to fire the flash, the shutter, etc.).