Was the transmitter on BEFORE you turned on the Phantom?
If so, and they are linked, then you have some other error.
Also, just to confirm, You've removed the gimbal lock before turning it on right?
The gimball will make a buzzing sound if it's locked when you turn it on.
The beeping is coming from one or more motors. Listen carefully and determine which motor is beeping or if all of them are.
Also note the LEDs flashing, colors and pattern.
Then let us know which motors are beeping and what the LED lights are doing.
If it's only one motor, you probably have a bad speed controller.
If it's all motors, there's something else wrong. I've checked the manual and can't find anything on beep codes or audio error indicators.
The motors beep when the ESC initializes. If the beeping continues it must be an ESC error.