Circuit boards for an electronic device are described. In one implementation, the circuit board includes at least two holes at two locations on the circuit board. Each of the at least two holes has a conductive contact coupled to a voltage source through a resistor. The circuit board includes a microcontroller programmed to measure voltages at conductive contacts of the at least two holes, and determine a position of the circuit board, when positioned on a conductive chassis of the electronic device, based on the measured voltages. The position of the circuit board may be one of a first end and a second end, and in between the first end and the second end, of the conductive chassis.