What does the red triangle error mean on the Android system?

In the absence of critical errors in the operation of the Android system, the operating system logo, the manufacturer’s icon, or the progress bar are displayed on the boot screen. However, if the Android fails to start, you will see its image accompanied by a red triangle and the inscription “No command”.

Why does the error appear?

The most common case in which important software fails is incorrect firmware installation by the user. For example, while using SP FlashTool, ADB Run, Odin3 or a similar application, the gadget was disconnected from the PC, which caused an unexpected shutdown of the process. In most cases, this happens by accident, but you should not pull out the connector yourself, even when the firmware is almost complete – wait until it is completely finished.

A tip to avoid such a situation: always charge the device before downloading the update by at least 30-40%. The best option is to have a fully charged battery, since installing the new functionality requires a long stay in data transmission mode, which causes high power consumption.

With the growing number of mobile device users, the number of viruses has also increased. If earlier Trojans that change settings and infect other files (for example, Skulls for Symbian) were the most dangerous, then modern hacker developments are able to make the gadget stop turning on, deleting the information necessary for the OS. To avoid similar situations in the future:

• Prohibit installations from third-party sources in the settings. You will still be able to download games, movies, music, books, programs from the Play Market store, files in which are manually and automatically checked;
• Download the antivirus. Do not abuse this point – just one such application is enough, simultaneous use of several will cause the device to slow down;
• Check the permissions of the existing software, remove the checkboxes from the “Change system settings” item for services that do not belong to reliable publishers, such as Google.

Recommended Anti-malware tool:

Method 1: Removing the battery (if possible)

If you have a phone with a removable battery in your hands – you are very lucky. Remove the battery for 10-15 minutes and insert it again. No matter how strange the description of this method sounds– it really works and helps when the problem is caused by flashing.

Method 2: Launch via Recovery mode:

Recovery mode is designed for cases when Android cannot be loaded. Go to it by holding down certain keys. The combinations vary depending on the brand, but a common way to open recovery mode is to simultaneously press the “Power” and “Volume Down” buttons before turning on.

Google:

1. Turn off your smartphone.
2. Press and hold the Power and Volume Down buttons until the menu opens.
3. Select Recovery Mode using the Volume buttons to navigate, and then confirm the action by pressing the Power button.
4. An image of an inverted “android” with an exclamation mark on its back will appear on the screen.
5. Hold down the Power button together with the Volume Up, release the Volume button after a few seconds, but keep holding the Power button.

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HTC:

1. Go to “Settings” → “Battery” and uncheck the box next to “Fastboot”.
2. Turn off your phone.
3. Press the Power and Volume Down button.
4. When the menu appears, select Recovery Mode using the Volume rocker and press the Power button to confirm the selection.

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LG:

1. Turn off your phone.
2. Press and hold the Volume Down and Power buttons.
3. When the LG logo appears, release the Power button, and then hold it down again (do not release the Volume button at the same time).
4. Use the Volume keys to select Recovery Mode, and confirm the selection with the Power button.

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Sony:
The first way

1. Turn off your smartphone and then turn it on.
2. When the company logo appears, hold down both Volume buttons and click on the Sony logo.

The second way

1. Turn off your smartphone.
2. Hold down the Power button until you feel a couple of vibrations, then hold down the Volume Up button.

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Samsung:

1. Turn off the device.
2. Hold down the Volume Up + Power + Home buttons.

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Xiaomi:

The first way

1. Turn off your smartphone.
2. Hold down the Power and Volume Up buttons.

The second way

1. Go to the Updater app.
2. Click on the three dots in the upper right corner.
3. In the menu that opens, select Reboot to Recovery mode.

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Some methods may not work, so look for up-to-date information on the official websites of your device manufacturer

After you have entered the Recovery mode, do the following:

1. Once in Recovery Mode, release the keys used to start it;
2. Select “Reboot system now“. If the touchscreen doesn’t work, try using the volume swing and the lock screen button to select an action.
3. The device will reboot to its normal state without data loss.

Method 3: Flashing the device with the official firmware

1. Download the archive with the firmware from the website of the manufacturer of your device
2. Upload a data archive to the root directory of the device storage, usually called update.zip. If it is called differently, rename it;
3. Log in to Recovery Mode using the instructions from the previous section. Navigation through the mode menu is possible, both with the help of the screen and through the buttons on the side panel – depends on the gadget. Find the item “Apply Update from update.zip“, which may also have a different name. In some cases, you may need to specify the path to the archive through an internal file manager.;
4. Do not turn off the device while transferring files. As soon as the process is completed, reboot – click on the “Reboot system now” button.

Method 4: Reset to Factory Settings

Go to this method if others have not helped you. This is an extreme measure, since these actions will affect the internal storage and affect the saved contacts (if they were in the phone memory), applications. You will be able to restore them thanks to the Google backup feature enabled by default on new versions of the operating system. However, some information will be completely deleted – remember the consequences. Therefore, we recommend that you make a backup of the data on Android.

1. Start up your device in Recovery Mode using previous instruction
2. Select the “Factory Reset” option, a notification will appear that it is impossible to reverse the changes;
3. After completing the process, restart the phone by clicking on “Reboot“.

In this article we have tried to describe all the main ways to solve the problem. If you know of other ways, please feel free to write them in the comments