Sony Magnescale LM20C‑22R is a dual‑axis (X/Y) digital readout controller used in precision motion systems. Common failure modes reported for this model include intermittent or permanent loss of signal on one axis, often accompanied by an “error” display on the Z‑axis port when the unit is miswired or overloaded; power supply ripple and over‑voltage can also trigger lockouts. First‑check diagnostics should verify that the 24 VDC input rail is within spec, inspect all cable connections for proper polarity and secure mating, and review any error codes displayed on the panel to isolate the affected axis. If an axis remains unresponsive after power verification, perform a continuity test of the output leads and check the controller’s internal I/O status LEDs for fault indications.[oss-gpt-20b]