This is a similar post as one in the new members area. I had the same problem. I read on the internet that, if it doesn't come up like it should, then hold the power button for up to 30 seconds. I am a newby to this forum and pads, but have over 35 years experience as an electronics tech. This problem didn't sit well with me, so I contacted Google tech folks.
They described this as a problem. They would have replaced it had I bought it from them. I bought mine from Game Stop (the only place in town that had the 16GB!) and they replaced it hassle-free. My advice is to have it replaced.