[Que]

I crashed my quad today and now I have no throttle control. It just goes fro nothing to full on.
 I'm thinking it must be an esc but I don't know how to check for that in this situation.
None of the  motors stutter after arming the quad. There is no excessive heat either.
However when I connect into Libre Pilot everything acts as it should. No 0 to 100 just smooth throttle response.
 I've rebooted the cc3d and re-adjusted the escs and it all seems fine until I take it out for a test flight.
Anyone have any ideas? I'm stumped.

[TheOtherCliff]

Does your PFD/HUD (Flight Data page) act right?  Moving the quad moves the display?

Rather than go through a lot of debugging on this, I recommend that you take the props off and do an ESC calibration and motor neutral setting.  That should fix a lot of the fixable ways it could be broken.
https://librepilot.atlassian.net/wiki/display/LPDOC/ESC+Calibration

[Que]

Hi Cliff,
Unfortunately I have done this a few times and still the same thing happens. The quad motors and ESCs act as they should while connected to LP and the HUD acts properly also, but as soon as I take it outside for a test flight the quad goes full throttle and flips to the front.
 I failed to mention (and you can shoot me later) that directly after the crash the quad was in the upright position so I just throttled up and flew it back to me. When I tried to land that's when I noticed a problem...I had trouble landing because there was no throttle response at the low end. It was either off or on there was no transition, It was as if I were just chopping the throttle.
 Shortly after I got home and hooked it up to LP the cc3d stopped working completely. it wouldn't light up when I conned it to LP and no longer lit up with a battery, so I switched out the cc3d (making sure that the orientation was correct) with another that I had and still the same problem, it's just either full throttle or nothing.
 That's why I figured it was one of the ESCs.
Anyway I'm stuck.
 Thanks for responding,
Que

[TheOtherCliff]

If you have set motor neutrals, then then motors are working correctly already.

If PFD works OK, then it should be fixable.  Have you looked at the Input section?  You might run "Start Manual Calibration" or set the min/neutral/max values to what they need to be.

If you have saved your UAV settings to a file, you could just import that file.

If you have the time, just erase and run the whole setup wizard again (maybe export UAV file first).

[Que]

Thanks Cliff I'll try that.

[Mateusz]

Shortly after I got home and hooked it up to LP the cc3d stopped working completely. it wouldn't light up when I conned it to LP and no longer lit up with a battery, so I switched out the cc3d (making sure that the orientation was correct) with another that I had and still the same problem, it's just either full throttle or nothing.

When you increase throttle, quad is trying to lift up and if it does not sense correct level it will keep giving even more thrust to motors to balance itself.
You mentioned you re-installed CC3D for new one, this might be the point when something went wrong.
If you installed your FC in wrong orientation or connected motors/esc in wrong order this might mean that FC senses rear motors need to be up, but since cables are in wrong order it actually lifts up front which is already to high and instead of balancing itself it just flips.

Check

• ESC cables order to different ESC channels on FC (this order is different then betaflight has) refer to picture in GCS
• Check if FC is oriented correctly with respect to 1,2,3,4 motors numbering. Where front and back is.
• Check if motors spin in the right direction and if propellers are mounted correctly correct motor and side of propeller.

Usually problems you describe with quad flipping and motors accelerating indicate that something is connected incorrectly or oriented not as it should be, and since you changed FC, you did quite a lot of things to the build where mistake is possible Hope that helps !

[Que]

O.K....After much adieu and finally just setting my quad aside for a few days (so frustrated I couldn't stand it) I have decided that there is an ESC that is not functioning properly. my question is this...is there any other way to determine which ESC is bad other than removing and replacing them one at a time until I find the bad one?
 
Thanks in advance,
Que

[TheOtherCliff]

Remove props.

The Output page has a "Test Outputs" checkbox which allows you to move some sliders on the PC with individual sliders controlling individual ESC / motors.