Maintaining the Motherboard Commonly used multimeter, which includes two stops
Using a digital multimeter to repair the motherboard, the main use of several gears.
1: diode gear: used to run the line, measure the resistance to ground, measure the line on and off.
2: resistance block is used to measure the resistance value of the resistor in the motherboard.
3: DC 20V voltage block, because the highest voltage on the motherboard is only 12V Repair of the motherboard is mainly by measuring the resistance to ground, and the ground voltage value to determine the fault, used to measure the current is too little.
Digital multimeter measuring gear: DC voltage (DCV), AC voltage (ACV), DC current (DCA), AC current (ACA), resistance (Ω), diode forward voltage drop (VF), transistor emitter current amplification coefficient (hrg), capacitance (C), conductivity (ns), temperature (T), frequency (f), check the line through the buzzer (BZ), low power method of resistance (L0). Power method of measuring resistance (L0Ω). Some instruments have inductance file, signal file, AC/DC automatic conversion, capacitance file automatic conversion range.
Most of the digital multimeters have added the following novel and practical test functions: reading hold (HOLD), logic test (LOGIC), true RMS (TRMS), relative value measurement (RELΔ), automatic shutdown (AUTO OFF POWER) and so on.
Notes on the use of multimeter:
(1) Before using the multimeter, it should be "mechanically adjusted to zero", i.e., when there is no measured quantity of electricity, make the multimeter pointer point at the position of zero voltage or zero current.
(2) In the process of using the multimeter, you should not touch the metal part of the pen with your hand, so as to ensure the accuracy of the measurement on the one hand, and ensure personal safety on the other hand.
(3) When measuring a certain amount of electricity, you should not change the gear at the same time of measurement, especially when measuring high voltage or high current, you should pay more attention to it. Otherwise, the multimeter will be destroyed. If you need to change gears, you should first disconnect the pen, change gears and then go back to the measurement.
(4) When using the multimeter, it must be placed horizontally to avoid errors. At the same time, it should also be noted to avoid the influence of external magnetic field on the multimeter.
(5) When the multimeter is finished using, the changeover switch should be placed in the maximum gear of AC voltage. If it is not used for a long time, the battery inside the multimeter should be taken out to avoid the battery corrosion of other devices inside the meter.
