A welding-type power supply comprising: power conversion circuitry configured to receive input power and convert the input power to welding-type power, the power conversion circuitry comprising: a rectifier circuit configured to rectify the input power; a pre-regulator circuit configured to receive the rectified input power and provide a regulated bus voltage; and a switched mode power supply configured to receive the regulated bus voltage and output welding-type power, wherein the switched mode power supply comprises four controllable switches (302, 304, 306, 308) configurable in a first topology and in a second topology, the first topology being a stacked full bridge topology and the second topology being a full H-bridge topology; a voltage sensor configured to measure a voltage difference between at least two nodes of the switched mode power supply, wherein each of the nodes is adjacent to at least one of the plurality of controllable switches; detection circuitry configured to: determine (406, 408, 412) if a configured topology of the switched mode power supply is the first topology or the second topology based on the voltage difference measured by the voltage sensor, wherein the voltage difference indicates if the nodes are directly connected and shorted with each other; and control circuitry configured to: compare the magnitude of an input voltage to a threshold to determine whether the input voltage corresponds to the first topology or the second topology; and prevent the power conversion circuitry from outputting welding-type power or the welding-type power supply from executing a start-up routine if the input voltage does not correspond to the configured switched mode power supply topology. a rectifier circuit configured to rectify the input power; a pre-regulator circuit configured to receive the rectified input power and provide a regulated bus voltage; and a switched mode power supply configured to receive the regulated bus voltage and output welding-type power, wherein the switched mode power supply comprises four controllable switches (302, 304, 306, 308) configurable in a first topology and in a second topology, the first topology being a stacked full bridge topology and the second topology being a full H-bridge topology; a voltage sensor configured to measure a voltage difference between at least two nodes of the switched mode power supply, wherein each of the nodes is adjacent to at least one of the plurality of controllable switches; detection circuitry configured to: determine (406, 408, 412) if a configured topology of the switched mode power supply is the first topology or the second topology based on the voltage difference measured by the voltage sensor, wherein the voltage difference indicates if the nodes are directly connected and shorted with each other; and control circuitry configured to: compare the magnitude of an input voltage to a threshold to determine whether the input voltage corresponds to the first topology or the second topology; and prevent the power conversion circuitry from outputting welding-type power or the welding-type power supply from executing a start-up routine if the input voltage does not correspond to the configured switched mode power supply topology. compare the magnitude of an input voltage to a threshold to determine whether the input voltage corresponds to the first topology or the second topology; and prevent the power conversion circuitry from outputting welding-type power or the welding-type power supply from executing a start-up routine if the input voltage does not correspond to the configured switched mode power supply topology.