HYY is a big Printed Circuit Board Manufacturer, when PCB board has some problem, we should know how to test and repair it with multimeter? Following methods have their advantages and disadvantages, combined these methods to use in practice. Good use will be able to repair all kinds of Printed Circuit Board.
1. DC resistance detection method, same to off-line detection, but we should pay attention to that disconnect the power supply from the testing circuit board, the internal voltage of the multimeter can not be more than 6V, and when measurement, note the impact of external.
2. DC operating voltage measurement method. Measured ic chip DC voltage, then just compared with the normal value is ok.
3. AC oprating voltage test method. Using universal meter with db to test the AC voltage approximation for ic.
4. Total current measurement. By measuring the total current ic power to determine the quality of ic.