Condition health monitoring strategies applied to different power electronics applications are gaining popularity as early component degradation detection can trigger preventive maintenance actions before a significant fault occurs. In highly modular converter structures, such as the modular multilevel converters, made out of many submodules, the development and implementation of condition health monitoring strategies are significant and challenging. This paper analyzes and demonstrates the use of the auxiliary submodule power supply consumption to recognize submodule sub-circuits abnormal operation. Thus, a new strategy to monitor submodules components is provided, enabling new prospective condition health monitoring methods locally or at the converter level. Experimental results show the effectiveness of the proposed idea.