pairing problems

I bought this unit used and it worked right out of the box; starting/stopping, pairing with the transmitter, viewing real time with the app etc. I was able to put in about 10 hours of flight time in before the issue I describe below began. After researching the available software etc I used the...

Hi! I recently bought a phantom 2 from dji's online store. I charged all of the battery's and setup everything the way dji said too. And then then upgraded the firmware, and then went to take for a test flight, but when powered on, I just got the yellow flashing lights of "no connection to...