A portable electronic device includes a main power supply, a power management unit (PMU) connected to the main power supply, and a receiver unit connected to the PMU. The main power supply supplies electric power to the portable electronic device through the PMU. The receiver unit includes a processor module connected to the PMU. The processor module stores a lock code, the processor module directs the PMU to prevent the main power supply from providing electric power to the portable electronic device when the receiver unit receives wireless signals corresponding to the lock code.