Abstract: A multi-function tester (10) for testing electrical continuity and detecting the presence of various types of voltages comprises a bistable flip flop (14) having set and reset input terminals (2, 6) which are driven by voltage changes thereat to change the level of voltage appearing at an output terminal (3), with the set input terminal being coupled to a voltage source (12) through a set resistor (30) and being coupled to a common terminal (26) through a TMOS FET switch (16). An LED (32) is connected between the flip flop output terminal and the common terminal. A storage switch (18) couples and decouples the set and reset terminals.