PX4 won't talk to computer after connecting

My name is Brandon. I’m working for a Photography business and I’ve just inherited the responsibility of building a drone. That part was easy. The Px4 in question was installed in a quad-rotor which was disassembled and used to create this hex-rotor while still configured for the quad. Once the batteries where installed I test powered the unit and all was well except the main led was solid red. Strange sense it worked a few days earlier in the other physical configuration. Now I’m trying to connect it to the computer to configure the px4 for the new set up and it doesn’t want to talk to Mission Planner. The computer finds it in Comport 3 but when I try to connect at 115200, Mission Planer claims it can not find a heartbeat after the 30 second countdown. I have not had a problem like this before and after 20 minutes searching the forums I must now turn to the reader for help.

Thanks for your time,
Brandon

What are you getting for lights on the Pixhawk and what sounds does it make when it starts up.

Sometime the unit does not connect and it may take a couple of times plugging and unplugging it.

Mike

As it turned out the SD card went bad. Id like to know if i may have done somthing wrong. I was told that I should of formated the card before powering on the px4. But I am sure the card is dead. Thanks you Mike for your response.