I have assembled my drone and calibrated esc also when I try individual esc callibration all motors are working fine. I have kk 2.1.5 flight controller board and I tried esc callibration there when I try to arm drone and it seems only 1 and 3rd motor spinning and 2 and 4 th motor not spinning I tried all methods and I didn't successes. If any one face same issue and any one know how to resolve this issue please let me know. Thanks.

@msnjsk,

Welcome to the forum.

Read the kk 2.1.5 manual.
If you have already done so, you would have found that it has a lot of info that needs time and effort to digest.

I suggest you look at Appendix G & H first (pages 22, 23, 24).
And read it again from page 1 thereafter.

http://dl.btc.pl/kamami_wa/hk_54299_7.pdf

Its been many years since I set up mine, so I'm not able to give you a solution straightaway.
I hope some of the quad experts in this forum will help.

Regards

Calibrate all the motors together. Keep the throttle stick at maximum and press first and last button in the kk board and connect the battery when the beeps stop reduce the throttle to minimum. Do it with props off

Hi S4ty thank, I tried multiple times but no luck  still same issue is there.