How to check Industry PCB? There are some skills:
First, observe whether the printed circuit board has been artificially damaged or not? Mainly the following aspects:
1. To see whether it was thrown or not, resulting the deformation of board angle or the chip board was wrestling deformation or broken?
2. To see the chip socket to see if there is no special tools but was forced to pry the bad?
3. To see the printed circuit board chip, if it with a socket, check whether it is inserted wrong or not firstly?
4. If the Printed Circuit Board has short-circuit terminal, check whether it is inserted wrong or not?
Secondly, check the printed circuit board components if it has been burned out. Normally, even the resistance burn paste, its resistance and property will not change, and it does not affect normal use, at this time, we need multimeter aided measurement. But if the capacitor and diode is burned, their performance will be changed, and can not play its due role in circuit and affect the whole circuit operation, then you must replace the new components.
Thirdly, Observe printed circuit board, if there has drum kits, cracks, burning paste, black situation, if yes, we can determine basically the chip has been burned and must be replaced.
Fourthly, observe the circuit board on the line if there is no skin. Fifthly, inspect the insurance on the circuit board, to see if the fuse is blown.