The Sokki Electronics JR205 is a magnetic rotary encoder used in servo drives, CNC machines, and industrial printers; it outputs either NPN/PNP collector‑open or RS422 complementary signals depending on the model variant. Common failure modes include winding insulation breakdown leading to open or shorted channels, misalignment of the magnetic sensor causing erratic counts, and contact wear on the encoder shell that can introduce noise or intermittent loss of signal. First‑check diagnostics should verify the supply voltage to the encoder, test each output channel for continuity and correct logic levels, and visually inspect the housing and wiring harness for corrosion, broken leads, or misaligned magnetic elements.[oss-gpt-20b]