A method for detecting a deficiency of an external compensation line for use in an external compensation pixel driving circuit connected to a data line, a power source voltage input end, a data write-in control end, an external compensation control end and the external compensation line, wherein each detection stage comprises a resetting time period and a detection time period,
- wherein the method comprises steps of:
- within the resetting time period of each detection stage, applying a resetting voltage to the external compensation line and entering the detection time period after a resetting duration;
- within the detection time period of each detection stage, controlling the external compensation line to be in a floating state, applying a data voltage to the data line, applying a power source voltage to the power source voltage input end, applying a data write-in control voltage to the data write-in control end, applying an external compensation control voltage to the external compensation control end, detecting a voltage across the external compensation line after a detection duration, and determining whether or not there is a short circuit for the external compensation line in accordance with the voltage across the external compensation line;
- within a resetting time period of a first detection stage, applying a first resetting voltage to the external compensation line, and entering a detection time period of the first detection stage after a first resetting duration;
- and
- within the detection time period of the first detection stage, controlling the external compensation line to be in the floating state, applying a first data write-in control voltage to the data write-in control end so as to turn off a data write-in transistor, applying a first external compensation control voltage to the external compensation control end so as to turn off an external compensation control transistor, applying a first voltage data to the data line, applying a first power source voltage to the power source voltage input end, detecting the voltage across the external compensation line after a first detection duration, determining that there is the short circuit between the external compensation line and the power source voltage input end in the case that an absolute value of a difference between the voltage across the external compensation line and the first power source voltage is smaller than a first voltage threshold, and determining that there is no short circuit between the external compensation line and the power source voltage input end in the case that the absolute value is greater than or equal to the first voltage threshold,
- wherein an absolute value of a difference between the first data voltage and the first power source voltage is greater than a second voltage threshold, an absolute value of a difference between the first power source voltage and the first resetting voltage is greater than a third voltage threshold, an absolute value of a difference between the first data write-in control voltage and the first power source voltage is greater than a fourth voltage threshold, and an absolute value of a difference between the first external compensation control voltage and the first power source voltage is greater than a fifth voltage threshold.