<p>This paper conducts a targeted failure analysis on the three most frequent typical malfunctions that account for the highest proportion of total failures during the repair of on-board recorders for a certain type of aircraft, namely failure of manual direction reversal during self-inspection, non-illumination of the three-channel OK indicator, and inability of the magnetic tape to reverse automatically, and proposes corresponding standardized troubleshooting procedures. Firstly, the recording device was disassembled in accordance with the repair process specifications. Secondly, a variety of diagnostic techniques, such as the instrument testing method, component replacement method, comparison method, and voltage measurement method, a hierarchical diagnostic framework is established, featuring board-level preliminary localization followed by component-level precise positioning, were comprehensively applied to conduct a thorough inspection of the electronic components and core parts inside the device, thereby accurately locating the fault points. Finally, Fault remediation is accomplished using a combined strategy of mechanical component calibration and circuit element reflow soldering. The implementation process and final results of the entire maintenance work show that the troubleshooting scheme proposed in this paper provides a practical and feasible reference for the efficient resolution of such faults.</p>