The basic approach to testing D/A converters is to:

• apply a sequence of binary codes covering the full range of input values to the circuit input while observing the output on an oscilloscope. The output should consist of a linear stairstep ramp.
• single-step the device through its full input range while checking the output with a DMM.
• check the output with zero input and then full input. The output of the converter should extend from zero to its maximum value. If so, then everything in between can be assumed to be operating properly.
• apply the correct input to the analog terminal and then check to see if the proper binary code exists on the digital inputs.