1 Diode
Analog multimeter, red pen is positive, black is negative. The diode cathode connects with red table pen, black pen to the anode of the diode, resistance should be around 20 ohms (use X1), contrary to measure resistance is infinite, the diode is good.
2 Transistor
Transistor can be considered equivalent to 2 diode docking. The measurement refer to diode, PNPN and NPN polarity is reversed.
3 resistors, capacitors
Resistance can be measured directly by a digital multimeter. The other are outside observation
Capacitor is to check for short circuit by a multimeter. The other are outside observation.
4 SCR
SCR is very common in the electrical components. There are three groups of SCR to form the rectifier voltage regulator to achieve power adjustment. To judge its quality is often measured with a multimeter resistance gear cathode and gate resistor, usually dozens of ohm. Measured with a digital multimeter to diode, polars are inconnected. Using analog multimeter's resistance gear measure the resistance between the cathode and the anode, usually a few hundred ohms.
5 MOSFET tube
460 MOSfet seen from the front, three pin from left to right followed by a gate, drain, source. MOS quality can be measured by DT9205A digital universal meter. Fingers don't contact the three pins. On reliable grounding metal platform, short circuit the three pins, then use multimeter to measure drain and source pins, resistance should be diode feature (200MΩWtap); then with thumb and index finger pinch the gate and drain, meanwhile measure the drain and source, resistance should be 4MΩ around (200MΩWtap). With this method also can rough measure MOS tube parameter's consistency.
