I Assembled Quad, 4 'X' shape. I Installed v3.5.4 firmware, calibrated sensors, flight mode configured. After that, i tried to arm the same. It's arming, but the BLDC motor didn't respond.
Still the same beep sound when i plugged-in the battery.
I Can't do ESC calibration, because it's not responding with the pixhawk commands. The RC is working fine.
I Checked it by disabling the Pre-Arm Checks. But still the same problem.