Signature Method of testing is also known as VI Trace Characteristics, is a proven fault diagnostics technique in power-off state while a board. By applying known wave from signal with desired voltage, Source impedance and frequency of the stimulus signals, depending upon

the test node and its characteristics, a voltage (V) vs current (I) graph is plotted and studied.

V-I Signature method is safe while testing components because the signatures are acquired without applying power to the board/device under the test. More importantly, the signature method can be used to test components even on a damaged PCB, which cannot be powered up for testing.

The trainer system also helps to plot Voltage vs Time and Voltage vs Impedance characteristics of the node under test in a board.