A display apparatus comprises a display array and an enable circuit. The enable circuit comprises a set of diodes and a set of transistors. The diode element comprises a first contact and a second contact. The set of transistors comprises a first contact, a second contact, and a third contact. The first contact of the set of transistors is connected to the display array. The second contact of the set of transistors receives a test signal to test the display array. The third contact of the set of transistors is connected to the first contact of the diode element. The second contact of the diode element receives an enable signal to activate the enable circuit.