In this study we applied both numerical simulation and experimental validation to characterize the thermal deformation of the panel and the direct-lit backlight unit (BLU) of a thin-film-transistor liquid-crystal-display television (TFT-LCD TV). Heat emitted from cold-cathode fluorescent lamps (CCFLs) causes thermal deformation of the LCD and extrudes the panel from the metal front shield at both upper corners: this finally leads to color distortion. In the numerical simulation based on thermal-fluidic fields of the TFT-LCD TV, natural convection of air that surrounded the CCFLs resulted in a high temperature at the upper-right and upper-left corners of the LCD panel. Numerical results were verified by temperature measurements with good consistency. Additionally, this study has established a measurement system to characterize the temperature distribution on both the BLU and panel and the thermal deformation of the panel causing the color distortion.