After replacing my dead kk board my quad flies.But while landing its unstable and comes down very quickly.I am using normal esc not simonk. Is it happening because of the slow rate of my esc?
450 self made frame
Emax motor
30amp esc

change your PI settings it settles it.

What is your P value?
Try decreasing it.
In what rate are you decreasing the throttle.

The pi values are set quitr low.

Thatt is also bad, first try with default values, reset your KK2.o and reload Motor setup .
Try again,
Also do you have previous experience in flying quad. (me too experienced much problems at first while landing, now rectified.)