A low power bypass circuit for use with a string of series-connected LEDs includes a semiconductor diode and resistor connected in series, which semiconductor diode and resistor combination become conductive upon the failure of an LED or upon the improper, reverse polarity connection of the string of series-connected LEDs to a power supply. When the semiconductor and resistor combination becomes conductive, a three-terminal gate-controlled semiconductor switching device becomes conductive, thereby bypassing the failed LED and protecting the integrity of the string of series-connected LEDs upon the improper reverse polarity connection of the string of series-connected LEDs to a power supply.