Memory in a Precision M6400

I know that there was another post on this topic, but I wanted to ask the following question.  I just purchased a refurbished M6400. It only came with 4GB ram (two 2GB sticks under the keyboard). I purchased 4 of Crucial 4GB Single DDR3-1600 ( PC3-12800) x4based, high density, 204-Pin SODIMM Notebook Memory CT51264BF160BJ. When I installed them I got a blinking CAPS Lock light.  I saw in the other post that this meant that the memory was assumed good.  I tried the memory sticks in each slot thinking maybe I'd find one bad.  The laptop works fine with the original memory sticks in it.  Am I right to assume that the memory sticks I bought may be bad?  I'm planning to return the four Crucial stick and get four Corsair sticks.  Can someone please advise?  Is it normal for the CAPS Lock light to blink for a certain period of time when adjusting to added memory?

Is there anything I need to do in the BIOS prior to installing the memory?  I've installed memory in my old Dell Latitude D620 and had no issues with it.