The Kwangwoo RAA‑000807‑2101 is an optical incremental rotary encoder designed for CNC turret and tool‑change applications, typically providing quadrature outputs at 24 VDC. Common failure modes in this class include loss of signal due to debris or misalignment on the shaft, insulation breakdown between channel leads, and contact wear on the output terminals; power supply ripple can also induce spurious counts. Initial diagnostics should verify a clean, stable 24 V DC supply to the encoder, inspect the shaft and housing for contamination or mechanical damage, and check each quadrature line with an oscilloscope for proper pulse shape and frequency. Finally, review any error logs from the host controller for missing or out‑of‑sequence counts that may indicate encoder degradation.[oss-gpt-20b]