How are the Components in Switching Power Supply Checked ?(I)

Resistance.

1) Visual inspection, incoming packaging should be intact without damage, clearly marked;

2)The color of the color ring is clear and easy to recognize, the color of the ring is in accordance with the nominal resistance, the pin is not oxidized and blackened, and the number is correctly marked.  .

3)The resistance value is consistent with the color ring label.  .

4) No rupture of resistance and shedding of coating layer;

5) No oil stains, water stains and other dirt on the surface. Dust caused by transport materials and capable of being blown away by air is acceptable.  .

6) Measuring resistance with multimeter.  .

7) With 30W or 40W electric soldering iron, the resistor pin shall be tin added, and the solder shall be able to completely wrap the pin.