Abstract: This disclosure describes systems, methods, and devices related to electron beam and nanoprobing techniques with probe tips for fault isolation in integrated circuits. A method may include generating a signal at a circuit device under test while a probe tip electrically interacts with a transistor of the circuit device under test; detecting, based on the signal and the laser at the transistor, an electrical output of the circuit device under test; and identifying, based on the electrical output, a location of a fault at the circuit device under test.