a sense circuit for detecting charge on a tft / lcd cell capacitor , which comprises a first , integrating circuit attached to the tft / lcd cell capacitor through a data line , wherein the data line is connected to the cell capacitance through a thin film transistor . the thin film transistor including a gate , a drain and a source , wherein the source is connected to the cell capacitor and the drain is connected to the data line . a first , gate supply voltage adapted to drive the gate of the thin film transistor . and a reset circuit adapted to reset the integrating circuit . this embodiment may further include a source for charging said cell capacitor prior to measuring the charge . further , a method of testing a partially constructed electronic circuit , for example the cell of an lcd , prior to installation of the backplate . the partial circuit comprising an array of contact electrodes , for example cell pad electrodes and an array of address electrodes , for example gate electrodes . the address electrodes being electrically connected to the contact electrodes . the method comprising the steps of providing the partial circuit with a test electrode , for example an adjacent data electrode extending alongside but spaced from at least a first contact electrode ; and measuring the capacitance between the first contact electrode and the test electrode .