Visual inspection: check whether there are obvious damage marks on the surface of the module, and then check the components for signs of cracking, missing paste, tin or even burning black.
Compare the parameters to see the difference --- if the visual inspection method looks good, you can use the relevant detection instrument to detect a new module with the same one and the module that may be faulty, and it can be divided into two cases of power on and power off. Check the voltage, resistance and waveform of circuit parts or components, and then compare the test results of the new module and the bad module To judge if something is wrong.
Replacement method to replace components and see the parameter changes --- if there are differences in the introduction of test parameters, the corresponding components or components of the module that may be faulty can be replaced with good product components or components of the same model, and then test the parameters again to see whether they return to normal.
According to a certain bad condition, determine the fault circuit area -- for example: poor optical power, mainly check the transmitting area, poor sensitivity, check the receiving area, etc., which can reduce the maintenance time and improve the efficiency.
According to the structure of the hanging light module, we can judge the components of the fault --- we all know that the optical module is mainly composed of Tosa component, Rosa component and PCBA board. If you want to judge the components of the fault, there are several methods to judge:
1. Remove Tosa components and Rosa components, and then test their performance on the component test board.
2. In the case of power on, use a multimeter to measure the voltage of each pin to see if the voltage value is normal; when the power is off, use a multimeter to test whether the circuit led out by the pin heel is connected.
3. According to the bad condition, test the corresponding parameters to see the change of the parameters. For example, if the bad reason is "low optical power", then the power of the module can be tested. If the power is increased, the reading of the power meter will increase, and the bias value of the bias current will also increase, and the working current will increase. This change shows that the PCBA circuit is on, and the drive performance and storage performance are no problem. It can be preliminarily judged that the optical power of Tosa is poor and the PCBA board is good, but it does not rule out the possibility of poor PCBA.
