Methods and apparatuses for controlling synchronous start-up of power converters arranged in parallel in droop load share switched-mode power supplies are described. In one embodiment, a method may be performed by circuitry in a DC-DC power converter. The DC-DC power converter includes an inverting switch that converts input DC power to intermediate AC power, a transformer coupled to the inverting switch to receive the intermediate AC power and provide stepped-down AC power, and a synchronous rectifier coupled to the transformer to convert the stepped-down AC power to output DC power. The method comprises detecting that the inverting switch is not switching during start-up of the DC-DC power converter, and increasing a reference voltage set point of the DC-DC power converter in response to detecting that the inverting switch is not switching to force the inverting switch to start switching.