Usually there are many integrated circuits in one device. When you get a device with a faulty integrated circuit, you must find out where the fault must pass. Testing methods that the ICs can effectively detect include: 1. Microprocessor integrated circuit testing The key test pins of the microprocessor integrated circuit are VDD power end, RESET reset end, XIN Jingzhen signal input end, XOUT Jingzhen signal output end and other each line input and output end. Measure the resistance and voltage of these critical feet to ground on the way to see if they are the same as normal values, which can be found on the product circuit diagram or in the service information. Different types of microprocessor RESET reset voltage is not the same, some low reset, that is, at power-on moment is low, reset to maintain a high level; some high reset, that is, the moment the switch is high, Maintain low after reset. 2. Switching power supply IC testing Switching power supply IC's critical foot voltage is the power supply terminal (VCC), excitation pulse output, voltage detection input, current detection input. Measurement of the voltage and resistance of the pin on the ground, if the difference with the normal value of the external components in its normal circumstances, you can determine the integrated circuit is damaged. Built-in high-power switch thick film integrated circuits, but also by measuring the switch C, B, E pole between the positive and negative resistance to determine the switch is normal. 3. Audio amplifier integrated circuit testing When checking the audio amplifier integrated circuit, it should first detect the voltage and resistance of the power supply terminal (positive supply terminal and negative supply terminal), audio input terminal, audio output terminal and feedback terminal. If the measured value of each pin data with the normal difference between the larger, the external components and normal, the integrated circuit is damaged. On the audio amplifier caused by silent fault integrated circuit, measuring the normal supply voltage, the signal interference method can be used to check. Measurement, the multimeter should be placed R × 1 file, the red pen ground, with black pen touch audio input, the speaker should have a strong normal "Titicaca sound. 4. Operational amplifier integrated circuit detection Use a multimeter DC voltage scale to measure the voltage between the op amp's output and the negative supply (at higher values ​​at static). With metal tweezers in turn touch the two op amp input (adding interference signal), if the multimeter needle has a more substantial swing, then the op amp intact; if the multimeter pin does not move, then the op amp is damaged. 5. Time base integrated circuit testing Time-base integrated circuits include digital circuits and analog circuits, with a multimeter is difficult to directly measure its good or bad. The test circuit consists of a RC element, a LED, a 6V DC power supply, a power switch S and an 8-pin IC socket. After the time-base integrated circuit (such as the NE555) is plugged into the IC socket, press the power switch S, if the time base integrated circuit under test is normal, the LED will blink; if the LED is off or on, it means the measured Time base integrated circuit performance is not good. Straight Reducing And U Type Tee,Equal Tee Equal ,Reducing Tee Pipe Tee,304 Straight Cross CHINA·SNGONG FLANGE MANUFACTURING CO., LTD. , https://www.sngonges.com