An electronic apparatus includes a system portion configured to operate with a received voltage, and a power supply including a pulse width modulation (PWM) generator to generate a PWM signal, a converter to transfer voltage from a primary side to a secondary side in accordance with an output voltage of the PWM generator, and an output portion to supply voltage at the secondary side as standby voltage to the system portion, the PWM generator receives feedback on the standby voltage at the secondary side of the converter, the PWM signal is turned on/off in accordance with levels of the standby voltage at the secondary side, and voltage being supplied to components, except, when the PWM signal is turned off, voltage at the secondary side is only supplied to a component that monitors the feedback of the standby voltage.