Coherent LQ10D321 is a 10.4‑inch Sharp industrial LCD panel originally equipped with dual CCFL back‑lights and a 640×480 RGB vertical stripe driver. Common failure modes include CCFL lamp burnout (often presenting as dim or uneven illumination), power supply degradation to the back‑light driver, and controller board faults such as broken signal traces or capacitor failures on the video interface. First‑check diagnostics: verify that the panel receives correct back‑light voltage and current from its driver; inspect the power supply rails for proper output and ripple; visually examine the LCD PCB for cracked solder joints or burnt components; review any error codes from the host controller if available.[oss-gpt-20b]