Common Accidents of Electric Soldering Irons and Their Maintenance
1) The soldering iron does not heat up after being powered on
When encountering this fault, you can use the ohm block of a multimeter to measure both ends of the plug. If the needle does not move, it means there is an open circuit fault. When the plug itself has no circuit failure, you can remove the bakelite handle and use a multimeter to measure the two leads of the soldering iron core. If the needle still does not move, it means that the soldering iron core is damaged and should be replaced with a new one. If the resistance value of the two leads of the soldering iron core is measured to be about 2.5 kiloohms, it means that the soldering iron core is good. The fault occurs in the power lead and plug. Most faults are lead wire breakage and plug contact disconnection. You can further use the Rx1 block of the multimeter to measure the resistance value of the lead to find the problem.
The method to replace the soldering iron core is to loosen the screw that fixes the lead of the soldering iron core, remove the lead, take out the soldering iron core from the connecting rod, then insert a new soldering iron core of the same specification into the connecting rod, and fix the lead on the fixing screw. And pay attention to cut off the excess wire ends of the soldering iron core to prevent the two leads from short-circuiting.
When measuring both ends of the plug, if the needle of the multimeter indicates close to 0 ohms, it means there is a short circuit fault. The fault point is usually a short circuit in the plug, or the crimping screw that prevents the power lead from rotating has fallen off, causing it to be connected to the lead post of the soldering iron core. The power cord is disconnected and a short circuit occurs. When a short circuit fault is found, it should be dealt with in time and the power should not be turned on again to avoid burning out the fuse.
(2) The soldering iron tip is charged
In addition to the reason why the soldering iron is electrified because the power cord is connected to the ground wire terminal, the other reason is that after the power cord falls off from the soldering iron core connection screw, it touches the ground wire screw again, causing the soldering iron tip to be damaged. charged. This kind of fault is most likely to cause electric shock accidents and damage components. For this reason, always check whether the crimping screws are loose or missing. If it is lost or damaged, it should be replaced in time (the function of the crimping screw is to prevent the lead head from falling off due to stretching and twisting of the power lead during use)
(3) The soldering iron tip does not "eat tin"
After long-term use, the soldering iron tip will become oxidized and no longer stick to the tin. This is the phenomenon of "burning to death", also known as not "eating tin".
When there is an inertia situation that does not "eat tin", you can use fine sandpaper or a file to re-polished the soldering iron tip or file out new stubble, and then re-plated with solder to continue using it.
(4) Pit appears on the soldering iron tip
When the electric soldering iron is used for a period of time, pits or oxide film corrosion will appear on the soldering iron tip, causing the shape of the blade surface of the soldering iron tip to change. When encountering this kind of situation, you can use a file to remove the oxide layer and pits, and then plate it with tin, and you can reuse it.
(5) In order to extend the service life of the soldering iron tip, the following points must be paid attention to:
1) Frequently wipe the soldering iron tip with a damp cloth or a water-soaked sponge to keep the soldering iron tip well coated with tin and prevent corrosion of the soldering iron tip by residual flux.
2) When welding, rosin or weakly acidic flux should be used.
3) When welding is completed, the residual solder on the soldering iron tip should be retained to prevent the appearance of an oxide layer when reheated.
