The most common causes

Almost all operators engaged in the sale of products, zamochennoy only under their services. That is purchased at a discount in the store the phone with already installed SIM card will not accept someone else if the owner decides to change operator. Solutions to this problem are two: first, you can continue to use the services of a previously selected company, finding that it provides the most acceptable rates, and secondly, you can try to unlock and reflash the phone, turning to the wizard. To engage in self-flashing, downloading the relevant application via the Internet, it is not recommended: it is likely that you will come across a paid program that will remove the old, and before final installation of the new offer to transfer money to someone's e-wallet.

The second possible reason is the oxidation or contamination of contacts of the slot. It occurs naturally as a result of prolonged operation and is eliminated by a simple cleaning. Helps an ordinary school eraser. The plaque can also appear as a result of wet contacts: dropping the cell phone in a puddle, his owner is not careful about drying it, and a few days later discovers that the phone does not see SIM card. Source temporary malfunction may be the condensate produced as a result of a rapid temperature change because of the transfer of the phone from the cold into a warm. You need to remove the cover, pull the battery and let the contents warm and dry.

Over time, the connection of the SIM card with contacts can weaken. In this case, remove the battery, pull the SIM card and insert it back. Helps also nested between it and the battery is folded several times a piece of paper, sealing the docking components. Of smartphones this element can wrap in a few layers of paper strips, avoiding contact, and then hold it, insert the SIM card into the slot.

When the intervention device does not require

If the phone number for a long time not in use: within a certain time for it are not performed chargeable operation (call, SMS) – the operator blocks the SIM card. After that connected to her room is laid out in a database freely sold. Inserting the item into the slot and found the problem, should immediately contact the center for cellular and unlock the "SIM card". It is enough to put on your account a small sum of money. If the number is not transferred, there is every chance to return it.