MODEL 100 TO OPERATE Set the selector switch to NPN or PNP. Disconnect power to circuit under test. Place the contacts of the tester in the correct position on the printed circuit board. The tester will emit a tone indicating that the transistor under test is a functioning unit. The absence of a tone indicates a shorted or open transistor. Setting the selector to the wrong position will cause no harm to your circuit. Maximum voltage applied to the base-emitter junction is 0.8 volts. Occasionally a shorted capacitor in the circuit will cause a transistor to appear bad. It is therefore recommended to re-test the transistor after removing it from the circuit. Because the transistors have a small amount of gain in the reverse direction, the tester may emit a very high pitch tone if the emitter and collector are reversed. For "IN CIRCUIT" tests the circuit impedance must be 100 ohms or more. Transistors coupled directly to each other (such as Darlington pair) must be disconnected prior to testing. Extender cables are supplied for use on large power transistors. The nose pins in the tester are internally wired to the tail sockets (i.e., nose pin E is wired to tail socket E, etc.). This allows the extender cables to be used in conjunction with the nose pins. For example: Two connections may be made to the printed circuit board by using the nose pins and the third connections by using the extender cables. WARRANTY The tester may be returned directly to Production Devices for repair, at no charge, if in warranty. If the 90 day warranty has expired, include check for $5.00 to cover repair and postage. PRODUCTION DEVICES 7857 RAYTHEON ROAD SAN DIEGO CA. 92111