A probe apparatus has probe wires with a contact pattern on one side. The contact pattern is for contacting a respective contact pattern on another test equipment or component, such as a circuit board. The probe wires have tips that probe a device desired for testing. Signals are transmitted through the probe wires from the probe card, for example, through a circuit board to other diagnostic equipment. The contact of the probe card with the circuit board allows signals to be transferred through the probe wires to the other diagnostic equipment. On another side of the probe card is a connector structure. The connector structure includes a retainer that can allow the probe card to be replaced from a test system, such as allowing it to be connected and disconnected from a holder.