This inspection of electronic circuits can be performed either by connection with voltage supply and without voltage supply. However, inspections during the working circuit may invite serious harm and damage to the components in the circuit. Usually, the method used is to measure the current and voltage values in the circuit based on the reading reference when the circuit is in normal condition. There is another method that can help check the current circuit condition by using image processing method. In this paper, we presented our study on electronic component failure detection using thermal image processing. The thermal image was collected from linear regulated dc power supply. The observation is focused on the thermal produce by capacitor and voltage regulator IC. The image has been analysed using Red Green Blue (RGB) and Hue Saturation Value (HSV) colour space. The pixel of colour was analysed using mean value. The result showed there is significant different heat produced by the component in normal condition and failure condition. Through the observation, it was found that the high heat was recorded if wrong polarity of the components in the circuit.