In the failure analysis (FA) of an organic light emitting diode (OLED) display device, fault isolation and physical failure analysis (PFA) were used to identify the root cause of display failure. It is challenging to conduct the FA of a display device, as it consists of display panel, a circuit board and components like semiconductor chips and this integration makes the failure complicated and difficult to analyze and understand. In the case of the display failure studied in this paper, the first work of fault isolation did not clearly identify the origin of the malfunction and its PFA didn’t show any specific defects. To precisely identify the defect location before destructive analysis, the fault isolation technique of OBIRCH was applied to the display device and subsequent PFA successfully identified a crack defect causing the display failure. This finding was given as feedback to the wafer fab and processing parameters were adjusted to prevent generation of the defect in the OLED display device.