Why Android phone won't receive mobile calls

Smartphones running under Android OS owners often face a problem with the failure of the basic functionality of their devices.

For example, a user of absolutely any mobile carrier might have to deal with the problem of the absence of a mobile network connection and the rejection of calls. Your phone might seem to be turned on and work with no failures, but other people can't reach you since the mobile provider informs them on your unavailability or the signal of a busy line sounds.

It's important to solve this problem as soon as it's detected, otherwise there is a possibility you can miss an important call.

The causes of the problem:

All the reasons why your phone won't receive calls can be divided into two categories:

1. failures in the hardware or software of your smartphone, 
2. problem with the cellular network.

Among the most common reasons on the part of the cellular network we can specify:

• The absence of coverage. Despite the prevalence of mobile networks and the constant development of new communication standards (3G, 4G, 5G), there are still places where there is no service (do-called dead spots). Most often, the problem can be encountered in a basement or remote areas. The solution: if your phone won't receive or make calls, try to move the device around and control the number of network strips shown on the screen.
• Mobile network crashes. If the base station of a mobile operator located in the area where you are is under repair or maintenance, you phone will receive calls from time to time. You can wait for the repair works to finish or connect to another base station via special tools for a phone.
• Mobile number blocked. Carriers have the right to block subscribers if they violate the rules of the service or if their accounts have insufficient funds. You can make sure if the blocking is your case by calling the blocked number. Instead of the standard message saying that "the subscriber is temporarily unavailable", the operator will notify you about the "temporary blocking of the subscriber". You can contact the operator in order to find out the reason why your phone won't accept incoming calls.

Hardware causes of the failure

Mobile Internet enabled

Quite a lot of smartphone users face the following issue: they can't be reached due to the mobile Internet being activated on their smartphones (mostly because of the connection to 2G networks). The solution:

1. Go to your smartphone settings;
2. Select "Mobile networks" item;
3. Select the needed SIM card;
4. Tap on "Preferred network type" and select 3G or LTE if possible.

If your phone won't accept incoming calls, these standards will allow you to receive calls from other subscribers and surf the Internet at the same time.

Two SIM cards in a smartphone

This problem is common for out-dated phone models with only one module for receiving the radio signal. Despite having two slots for SIM cards, while one card is being used, the other one is simply unavailable. The only solution is to purchase a smartphone with two radio modules.

Problem with a radio module

The owners of absolutely any device running under Android may face such problems. The solution:

1. Hold down the device Power button for a few seconds;
2. Wait for the smartphone to turn off;
3. Turn it back on after 10-15 seconds.

Another method is to start your device in the Flight Mode through the settings or the top context menu.

Faulty SIM card or slot

If your SIM card is faulty, incoming calls won't be received by any device. You can identify the damage in the following ways:

1. Try inserting your SIM card into another phone.
2. If it receives signals, then the problem is with the SIM card slot.
3. If this SIM card can't be registered in the network on another device too – contact the nearest office of your mobile provider and ask for the replacement of the SIM card.

Problem with IMEI

If the current IMEI of your phone doesn't match the factory IMEI, the smartphone may stop receiving mobile calls from other subscribers. Most often, such problems can face users who have performed reflashing of their devices from one OS to another on their own.

The solution:

1. Determine the current IMEI code of your smartphone by dialing *#06#.
2. Compare the number displayed on the smartphone screen with the combination on the box of the device. If the box is missing, you can check the factory IMEI on the picture under the battery of the device.
3. If both codes match, the root of the problem isn't in the IMEI. In case this data doesn't match, you should contact the service center in order to recover the device.

Software problem

If third-party or malicious software, beta apps working with failures or call blockers are installed on your phone, it will reject incoming calls, and other subscribers won't be able to reach you.

The problem solution:

1. Get rid of all suspicious apps on your smartphone.
2. Install antivirus software on your phone and check the device for viruses.

As a last resort you can reset the smartphone back to its factory settings (note this will delete all personal data and downloaded files).