Abstract: Some embodiments include apparatus and methods to test a device having a driving layer and a sensing layer. A test signal is applied to electrodes of the driving layer in a capacitive load state, with a capacitive load applied, and in an ambient state, without a capacitive load applied. Measured values are obtained at the sensing layer for each state. The measured values are compared with threshold values. A report is generated when a measured value violates a threshold. In one embodiment, the driving layer and the sensing layer form multiple capacitive electrodes within a touch sensor. The measured values are related to mutual capacitance values of the touch sensor.