Illustration of the measurement method of field effect tube

The following is the measurement method of the field effect tube
Field effect tube English abbreviation is FET. It can be divided into junction field effect transistor (JFET) and insulated gate field effect transistor (MOSFET), which we usually referred to as MOS tube for short. The MOS tube can be divided into enhanced type and depletion type. What we usually use in motherboards is the enhanced MOS tube.
The picture below shows the logo of the MOS tube

The three pins of MOS tube G D S commonly used in our motherboard are fixed. . . It does not matter whether it is an N-channel or a P-channel. . . Put the chip upright. . . From left to right are G pole, D pole and S pole! As shown below:

Use the diode file to measure MOS tube. . . First, short-circuit the three pins to discharge the tube. . .
1. Then connect the red test lead to the S pole. The black test lead to the D pole. If it has a value of more than 500, it means that the tube is N-channel..

2. The black pen does not move.. Use the red pen to touch the G pole and the measured value is 1

3. Move the red pen back to the S pole. At this time, the tube should be on...

4. Then the red pen is used to measure the D pole. The black pen is used to measure the S pole. The value should be 1. (Pay attention to this step. Because the voltage of the G pole 2.5V multimeter was given in the previous measurement.. So it is still between DS It is turned on.. But it will return to normal after about 10 seconds...It is recommended to short-circuit the three pins again to discharge the tube when this step is performed)

5, then the red pen does not move. The black pen is used to measure the G pole. The value should be 1

At this point, we can determine that this N-channel field tube is normal

Some people say that the next two steps can be omitted...but I habitually use all five steps. . . Of course. The measurement steps of the P channel are the same...except that the step is to measure the S pole with the black probe, and the red probe to measure the D pole.. It can measure more than 500 values...
This is the end of the description of the measurement method...