The mouthpiece problem in mobile phone is mostly caused by the malfunctioning of a small component called mouthpiece, it is usually found at the base of the phone when held in a call position. The problem makes it impossible for people to hear from you whenever you initiate a call. The problem resulting from the mouthpiece is multi-faceted. The following among others could be responsible for a mouthpiece problem in a mobile phone.
Phone Mouthpiece Problem, Possible Causes And Solution:
- High/Low resistance value
- Bad/partial contact
- Short or open circuit
High/Low Resistance Value
The resistance value of a healthy mouthpiece ranges between 600 to 1800 Ohms using the Ohms meter. So when the resistance value is lesser than 600 Ohms your mouth piece is louder so people can hear you even louder than usual and when the mouth piece is higher than 1800 Ohms people will hear you very faint and this is because high resistance opposes the flow of current required for the mouth piece to function properly. To fix this problem, simply buy a new one or get a scrap phone, remove the mouthpiece and using your soldering iron, solder it to the mouth piece interface of your phone taking note of the positive and negative wires.
The negative wires are black colored while the positive wires are red, or yellow colored mostly in the case of universal or wired mouth piece. For other mouthpiece that used flakes, just connect with jumper wire if you notice there is a break and that will be okay.
There are some other mouthpiece that are surface mount in the sense that they are soldered on panel or PCB [Printed Circuit Board] of the mobile phone, in this case you would need a mobile repairing equipment called the rework station and this is mostly used by professional technicians for doing a lot on the PCB including the removal of surface mount or soldered mouth piece. If you do not have access to the rework station, then you will have to visit a care center for a more professional service.
Oxidation is also another cause of mouth piece problem. This happens when the mouth piece region has become moist and covered with some dirty particles over a long period, the chemical reaction result in a faulty mouth piece that has to be changed for normal functioning again. Although there are times that just a mere cleaning of same oxidized surface with alcohol or menthylated spirit using a tooth brush could solve the problem.
A bad/partial contact
A mouth piece problem can also result from a bad contact, meaning that there is either a partial or total disconnection between the mouth piece and the interface it is supposed to be connected to. What you would simply do in this case would be to just tighten the phone more with screw driver, or you locate disconnection and solder appropriately, and with that your phone’s mouth piece would be back to normal.
Short or open circuit
In a layman’s word, a short circuit simply means that a component has been bridged in the phone’s PCB or board. Short is caused when a diode, a capacitor or some other IC [integrated circuit] in the phone are internally bridge for one reason or the other e.g water damage, conducting materials in between internal components. In this case you might need the services of a professional, but before heading for a professional, after dissembling the phone, try and see if you can locate any foreign particle that could be bridging other component together and remove them as this sometimes even solves the problem thereby saving you money, time and energy.
An open circuit on the other hand, means that there is a total or partial disconnection as a result of a missing or damaged path or parts, and this can also happen internally which means you will need to troubleshoot with the help of block diagrams for the phone under consideration. In this case a special troubleshooting becomes necessary and only a better trained experience technician would handled that, but you could try something out too. Just check if there is a noticeable wire disconnection from the mouthpiece and solder it back to position with the help of your soldering iron.