This paper analyzes the fault tolerance of non-isolated, modular, high gain dc-dc boost converter under different fault conditions. In the absence of transformer isolation, there are safety concerns in high gain converters in ensuring that high voltage stress is not applied to low voltage ports under any component failure conditions. The main idea is to increase the reliability of converter operation by making minimal modifications to the actual converter and control scheme as well as minimal component addition. Fuses are incorporated in the converter and their control co-ordination with different phase switches is proposed to ensure normal operation under various faults. The proposed method is discussed and implemented to ensure normal operation of converter under different component failures and verified through simulation results. The main faults under consideration are the short circuit fault and open circuit fault of the MOSFETs, diodes and coupling capacitors. The discussed methods are analyzed, tested and validated with a 35V-600V, 500W 4-phase hardware prototype.