The compact and portable Faultfinder VIP system, combined with a Laptop running TestVue software, provides a way to rapidly identify failures by troubleshooting a PCB or CCA. It uses impedance signatures (also known as VI testing) measured from a known working circuit and stores them as a test program. These stored signatures are then compared to the ones being measured on the suspect circuit to automatically determine if there is a fault.

The technique does not require any knowledge of the function of the circuit and is a power-off test technique. It is therefore a safe and rapid way to test a circuit when there is no test information available.