How to repair an electric soldering iron that does not generate heat after being powered on
There are two situations where an electric soldering iron does not heat up after being powered on. One is that it does not heat up at all after being powered on, which may be due to damage to the soldering iron core or power cord. At this time, a digital multimeter can be used to measure the resistance between the plugs of the soldering iron power cord. Generally, the resistance of a normal soldering iron is between 110 ohms to 12 kiloohms (the higher the power of the soldering iron, the smaller the measured resistance). If the measured resistance is infinite, it may be due to damage to the soldering iron core or power cord. Simply replace the soldering iron core or power cord.
If the electric soldering iron remains slightly hot for a long time after being powered on and cannot melt the solder wire, it may be due to a thick oxide layer attached to the inner wall of the soldering iron head, which hinders the heat transfer from the soldering iron core to the soldering iron head. Some cheap electric soldering irons do not have temperature adjustment and constant temperature functions, and use the copper soldering iron head shown in the above figure. If heated for a long time, the copper soldering iron head is prone to oxidation at high temperatures, producing a high thermal resistance oxide that adheres to the inner wall of the soldering iron head, causing the heat generated by the soldering iron core to be unable to be transmitted to the soldering iron head normally, thus preventing the melting of the soldering wire.
If the soldering iron head is severely oxidized and cannot be welded properly, it is recommended to replace it with a better and adjustable temperature electric soldering iron, as the quality of the soldering iron has a significant impact on the welding quality. The temperature adjustable electric soldering iron shown in the above picture is priced at just over 20 yuan. It has a built-in temperature adjustment circuit and the soldering iron head is made of alloy, which is not easy to oxidize and black at high temperatures, making it very convenient to use.
An electric soldering iron is composed of several parts, including a soldering iron head, a soldering iron core, a metal shell, a wooden (plastic) handle, a wiring post, and a power cord. The heat source of a soldering iron is the soldering iron core installed on the head. As long as the soldering iron core is powered on, it can work normally.
If the soldering iron is not hot, the first step is to use a multimeter to measure the resistance of the two pins of the power plug. Under normal circumstances, the resistance value should be between a few hundred to several thousand ohms. If it is in an open circuit state, you need to open the handle to check if the wiring is firm and reliable. Then measure the wiring terminals,
