Sony Magnescale LH30‑2 is a digital read‑out (DRO) unit used on CNC machine heads such as Bridgeport J‑heads to provide real‑time position feedback. Common failure modes for this model include loss of display output due to board component degradation, power supply voltage drops or brownouts, and signal line faults between the DRO and the machine controller. First‑check diagnostics should verify that the unit receives its rated 12 V DC (or specified) input without ripple, inspect all solder joints and connectors for corrosion or breakage, and confirm that the DRO’s serial/parallel I/O lines are correctly wired to the host controller by checking voltage levels and error codes if available.[oss-gpt-20b]