GPS flying suddenly started wandering a lot.

[koviatt]

Hey all, I recently updated my unit to 3.12. Was hovering the heli in the shop. A blade failure (won't go into that here) resulted in a terrible vertical surge and the heli slammed into the celing and then a hard drop to the floor. I replaced the blades and took the unit outside this time. When I got it powered up and steady green I flew it, but noticed that the GPS hold is not holding very well. When I yaw in a gentle spin on its axis, the heli drifts terrible in one direction. Like 30-40 feet. If I yaw the other direction it does the same thing but in the opposite direction. it acts like it is tryign to return to its original spot, but just is not that committed any more. No winds. Before all this drama, the heli would rotate on its axis and not drift a bit, even in wind. Now I can't trust her to hold still.

On the spot, I did a GPS/Compass recalibration and did not see much improvement. So I brought her back in and ran an advanced IMU calibration. No errors or issues. All seemed okay with the calibration process itself, the phantom will fly, but the GPS just seems "off" or "weak."

What do you all think?

 

[jumanoc]

Hey all, I recently updated my unit to 3.12. Was hovering the heli in the shop. A blade failure (won't go into that here) resulted in a terrible vertical surge and the heli slammed into the celing and then a hard drop to the floor. I replaced the blades and took the unit outside this time. When I got it powered up and steady green I flew it, but noticed that the GPS hold is not holding very well. When I yaw in a gentle spin on its axis, the heli drifts terrible in one direction. Like 30-40 feet. If I yaw the other direction it does the same thing but in the opposite direction. it acts like it is tryign to return to its original spot, but just is not that committed any more. No winds. Before all this drama, the heli would rotate on its axis and not drift a bit, even in wind. Now I can't trust her to hold still.

On the spot, I did a GPS/Compass recalibration and did not see much improvement. So I brought her back in and ran an advanced IMU calibration. No errors or issues. All seemed okay with the calibration process itself, the phantom will fly, but the GPS just seems "off" or "weak."

What do you all think?

Hey,i think the GPS panel board or connection point are broken. That is a very thin surface. Open shell peel off GPS gently, and verify for broken sings in it.

 

[koviatt]

jumanoc, thanks for the reply.

Yes, I will disassemble and check this for any obvious damage.
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Ok, I removed and inspected the GPS module carefully. No visible damage or cracks. Also carefully inspected all the solder connections between the two boards on the mudule under a microscope. No fractured solder traces.

So my question now is this: Would the heli "acquire" satellites and resolve start up to a regular green light if the GPS were damaged?

 

[snapdog]

Look at this suggestion from another reply. May help.
viewtopic.php?f=5&t=82&start=10