1, offline detection: the positive and negative resistance values between the pins of the IC chip are measured, which is compared with a good IC chip to find the fault point;
2, online detection: DC resistance detection method is the same as offline detection. However, it should be noted that to disconnect the power supply on the circuit board to be tested, the internal voltage of the multimeter should not be greater than 6V, and the influence of the periphery should be paid attention to when measuring.