[hdrider]

when I plug in the flight controller to the usb it is not recognized. I thought I had a bad controller and installed a new one and the same result. any help is appreciated.

[Brian]

If it's the controller that came with the eachine 250 it probably has cleanflight or something similar installed, which means that you're going to have to first flash an LP bootloader, assuming the board is supported by LP.  What type of FC board is it?

[hdrider]

This is the CC3D that came with the quad copter

[Brian]

It probably needs the LP bootloader flashed on it.

This describes the steps required to install the bootloader: https://librepilot.atlassian.net/wiki/display/LPDOC/Recover+board+using+DFU

The SBL pads are probably in a different place than in any of those pictures.  I got one of these kits recently and haven't done anything with it yet.  If you have the same FC and I have, it looks like the SBL pads are to the lest of the big arrow.

[Brian]

I checked my CC3D'ish FC that came with the Eachine 250, and it actually has the OP bootloader on it, so I was able to flash it with LibrePilot directly from the GCS.  I normally use Rescue mode to flash, but I'm not sure that's required.

[f5soh]

Hi, welcome.

First take a look at led activity when you plug the USB connector on it. What happens ?

Take a look here for firmware update:
https://librepilot.atlassian.net/wiki/display/LPDOC/Firmware+Tab#FirmwareTab-UpdateBootloaderandUpdatefirmware

For what i know the CC3D board do not support DFU, you may need to flash bootloader using a FTDI, if needed.
http://www.southquay3d.com/index.php?route=news/article&news_id=9