Crash after few seconds

Hi, can you help me with investigation ? Copter starts to rotate after few seconds in Alt hold mode and then crash. Log: 2018-04-11 (291.7 KB)

Test: IMU Mismatch = FAIL - Check vibration or accelerometer calibration. (Mismatch: 1.52, WARN: 0.75, FAIL: 1.50)

Not good. Check vibration and or recalibrate the IMU there is also evidence of clipping from vibration.

Z vibes were up around 40…

Hardware failure.
Looks like motor 1 failed, or the prop came loose, or similar.
Motor 1 goes to max, motor 2 goes to min to try and compensate.

There is a vibration event at that time.
Motor loose?
Prop loose?
Something failed.

Hi, thank you for replay. I have replaced motor 1 but it is still crashing - today 2 accidents (546.1 KB). Btw - it is not new setup - last year (before winter) I had no problem.

You have a problem with motors 1 and 2.
It may be a desynchronising effect.
Have you checked all your cables?
Do you have bullet connectors?

If you log the RCout you will see what I am referring to.