[bmw111]

Strange one here. Hoping someone can point something out before I go down multiple paths looking for a solution. I have two quads, both use the exact same CC3D board, same FW, never had any problems connecting either board to the PC and GCS -- until today. I flew some tuning flights with one, multiple connections to the PC in the field, no problems connecting and saving. Came home, plugged in the other to the PC and GCS will "connect" but only shows one green LED segment in the Tx and none in the Rx. Powering with battery, having Tx ON/OFF doesn't make a difference. Tried different USB cables, restarting the PC, power cycling the quad, nothing. Plug in the other quad that had no problems and everything works perfectly, connection great. Unplug that one, plug in the other one, bad connection. I can fly the "bad" quad, everything works as it should -- for some reason, suddenly today it decided to stop connecting to GCS (or at least stop giving a good connection to GCS). Any thoughts?

[f5soh]

See Troubleshooting page:
https://librepilot.atlassian.net/wiki/display/LPDOC/Troubleshooting

Every board is registered with a driver.

[TheOtherCliff]

When you plug in the bad FC, do any LEDs on the FC light up?

You may try plugging in a flight battery for power to see if that allows USB to work.

[bmw111]

Yes, I tried with flight battery plugged in. Board does get LED lights without flight battery. I was hoping it wasn't a driver issue, but it looks like it may be. I'll try f5soh' suggestion. Questions -- Why would one board work and the other doesn't, when only one day ago they both worked fine? I don't recall installing any new drivers. Will they both work again, or will the "bad" one now connect and the "good" not connect?

[ernstock]

I have a board that is similar. Lights all good , flies fine but won't connect.
Reason in my case is a damaged USB port on the board - I now file of the catches on USB cable plug to lessen the chance of damage when disconnecting.

[f5soh]

Why would one board work and the other doesn't, when only one day ago they both worked fine?

Every board is registered with a driver.
Board can be the same model but differs because the serial are not the same.

[TheOtherCliff]

One easy test is to install GCS on a different computer and test there.

If bad board stays bad, and good board still works, then "bad board" is probably the problem.

[bmw111]

Thanks for everybody's comments. The driver reinstallation solved the problem.