Heidenhain 220 10801 Scale Encoder is a sealed linear encoder module used in CNC and servo‑controlled machine tools for high‑precision position feedback. Common failure modes include optical signal loss due to dust or grease on the scale tape, mechanical wear of the scanning carriage, and electrical degradation of the photodetector array or drive circuitry. Initial diagnostics should verify that the power supply voltage matches the encoder’s rated input (typically 24 V DC), inspect the optical path for contamination and ensure proper alignment of the scanning head to the scale, and check the output signal integrity with an oscilloscope or logic analyzer for missing pulses or noise spikes.[oss-gpt-20b]