When using the instrument, how to judge whether there is a fault

1. First observe whether the components are damaged, discolored, bubbles or burnt spots; burnt devices will produce some special odors; short-circuited chips will be hot; virtual soldering or desoldering can also be observed with the naked eye. Often encounter the phenomenon of good and bad when the instrument is running. Most of this phenomenon is caused by poor contact or virtual welding. In this case, tapping and hand pressing can be used. Potential failure areas to see if it will cause an error or downtime.

2. Sometimes, the instrument will work for a long time, or when the temperature of the working environment is high in summer, it will malfunction. Shut down and check normally, stop for a period of time and then restart it normally, and then malfunction again after a while. This phenomenon is due to the poor performance of individual ICs or components, and the high temperature characteristic parameters do not meet the index requirements. In order to find out the cause of the failure, the heating and cooling method can be used. The so-called cooling is to use cotton fiber to wipe the anhydrous alcohol on the part that may fail to cool down when the failure occurs, and observe whether the failure is eliminated. The so-called temperature rise is to artificially raise the ambient temperature, such as using an electric soldering iron to approach the suspicious part (be careful not to raise the temperature too high to damage the normal device) to see if the fault occurs.

3. In general, before the fault is determined, do not touch the components in the circuit, especially the adjustable devices, such as potentiometers. However, if the double reference measures are taken in advance (for example, the detection instrument should mark the position or measure the voltage value or resistance value before it is touched), it is still allowed to be touched if necessary. Maybe after the change sometimes the glitch will go away.