This is how you can test a transistor with a multimeter
First of all, the digital multimeter "diode and buzzer" gear to determine the good and bad transistors and transistors are PNP-type or NPN-type.
① digital multimeter dialed to "diode test" gear, the red pen into the (VΩ) jack, the black pen into the (COM) jack. For the red pen access to a foot, the other two feet resistance value of 611 Ω or 614 Ω, it is said that this time the measurement of the triode for the NPN-type tube, 611 Ω a few small resistance value of the collector of the triode, 614 Ω of the emitter of the triode set. Conversely, the black pen of the digital multimeter connected to a foot and in fact the other two feet are in the 600Ω or so of the triode for the PNP-type triode, or resistance value of a small foot for the collector of the triode, a little bit of resistance value for the emitter.
If the three feet with red and black pen measurements, how can not measure the 600Ω resistance value of the triode, it is bad. If the measured resistance value is less than 600Ω too much or zero, proving that the triode is bad.
Sometimes although they can measure the resistance value of the triode of 600Ω or so, at this time must also use the multimeter to measure the emitter and collector set of forward and reverse resistance value between them, intact triode, e → c, c → e resistance value is ∞ infinity, otherwise prove that the triode has a question to mention.
Note; for the band damping diode and base and emitter with damping resistance except.
② For a good determination of the PNP or NPN triode, this time you can pull the digital multimeter to the hFE block, this block is dedicated to the measurement of low-power triode jack. Insert the three legs of the triode into the right number, at this time the digital multimeter will show the amplification of the measured triode.
