A novel integrated fault diagnosis method of 8 bit Digital to Analog Converter (DAC) circuit is presented in our paper. The circuit is based on the one presented in the IEEE 1997 International Test Conference (ITC'97). The gain waveforms of faulty and faults free (Golden) circuits as well as internal node voltages of two stage CMOS Operational Amplifier is used to detect the faults. An assembled fault detection procedure is introduced along with its localization and percentage of detectable faults estimation using HSPICE and MATLAB. This type of test is defined minutely accurate and effectiveness of it in detecting faulty circuit is evaluated.