Motors not spinning issue in Mission Planner

Dear Sir/Madam,
We are using Pixhawk 2.4.8 flight controller for flying the Quadcopter in the Arddupilot .Unfortunately,We are constantly facing an issue that is Motors are not spinning even after the copter is armed.We had also checked all the motor working conditions individually, all are in proper state.Additionaly,We are using Simonk 30A ESCs for calibration,When we had calibrated there was no constant beep noise coming. Please guide us to overcome this issue.