At the end of the 30-minute treatment the intensity immediately goes to zero, but the unit dies not turn off. It beeps 3 times at the end and then sits in a pause mode (all 5 white bars are on) for about 5 minutes after which the unit will automatically shut off. If you disconnect the cable from the unit or disconnect the cable from one or both pads before you press and hold down the power button to turn it off (in other words while the unit is still in the pause mode) then the unit detects a break in the connection and beeps orange. Then you just need to press and hold the power button for 2 seconds to turn it off.