A soldering iron is used to solder the spare parts on the green coloured PCB (Printed Circuit Board) of the cell phone. These soldered parts may get disconnected, lose contacts with the PCB or simply come out over time. They may also come out due to shock or jerk due to falling down. Hence you will need to solder the parts back again using a soldering iron. It is also called soldering station by many cell phone repair technicians.
Soldering is a skill which you can learn only with good training as well as lots of practice. In cell phones, as the parts and their connections are small, you will need to make yourself well versed with it. Soldering in cell phones is a little more difficult as compared to doing it in LCDs, computer motherboards and laptops. You can learn to solder by even watching videos but lots of practice is the key to master the art. I know of many DIY type of people who have learned the art without any formal training. You can practice on some dead phones by desoldering and then resoldering the parts back.
The most common things you will need to solder are
- Charging port
- Headset connector
- Battery connecting
- Power button
- LCD (In some handsets, its soldered!)
- And many more spare parts
In Chinese handsets, almost all part is soldered including mic, speakers and loud speaker (ringer). I still do not know the logic behind it but the most obvious reason may be to reduce costs!
You will need the soldering iron also to make jumpers if any of the tracks are broken. This is done only if you are doing advanced repairs on the motherboard. If you do not do advanced troubleshooting and do not repair circuit boards, you do not need to make jumpers.
Read: How to make jumpers in mobile phone repairs
So how to use soldering iron in cell phone repairs
- Clean the points on the PCB you have to solder with the soldering iron itself and make them flat.
- Switch on the iron and keep it on for around 2 minutes so that it become very hot.
- If you are right-handed, hold the part which you have to solder with the left hand and solder it with the right hand. If the part you want to solder is minute or small, you will need to hold it with tweezers.
- Take some solder wire (as per your need) on the tip of the solder iron, put the part you want to solder and touch the point where you want solder it. When you see its stuck properly, leave the tip and do not move anything until the joint cools down and manually check it. If its nor proper, repeat it until its stuck properly.
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