Many owners of outdated tablets are faced with a situation where the manufacturer stops releasing updates, and current applications stop running on the old version of the system. Android 7.0 Nougat has become a kind of golden mean, providing decent performance even on the budget hardware of yesteryear. Trying to bring back to life a gadget released in 2013–2015 can be an exciting process, but it requires careful preparation.
The process of replacing an operating system, or custom firmware, is radically different from a regular over-the-air update. You will have to work with the bootloader, get root access and manipulate system memory partitions. Errors at any stage can turn your tablet into a “brick,” so it is important to understand the essence of each action before you begin custom firmware
In this article we will analyze the algorithm of actions for installing Android 7 on devices of various brands, including Samsung, Lenovo and Asus. We will not make empty promises: not every device supports new versions of the system due to limitations of processor drivers. However, if enthusiasts have already created an unofficial port, you can significantly extend the life of your device.
Checking compatibility and selecting firmware
The first and most critical step is finding suitable software. It is possible to officially update the tablet to Android 7 only if the manufacturer has provided for such an opportunity, which is rare for older models. Most often you have to look for custom builds from the developer community, for example, on a forum 4PDA or resource XDA Developers.
You need to know exactly the model of your device and, more importantly, the type of processor. The architecture ARMv7 or ARM64 determines which versions of the system can physically be run on the chip. Trying to install firmware for a processor Mediatek on a device with Qualcomm Snapdragon is guaranteed to cause damage.
⚠️ Attention: Never use firmware designed for other models, even if the names of the screens or cases are similar. Differences in pinouts may cause a short circuit or permanent failure of the bootloader.
When searching, pay attention to the assembly status. Stable versions (Stable) are suitable for daily use, while nightly builds (Nightly) may contain critical bugs. Also check the list of working functions: often the camera, Bluetooth or proximity sensor do not work in custom firmware.
Preparing equipment and backup
Before making changes to the software part, it is necessary to create a complete copy of all user data. The process of installing a new system involves completely clearing the internal memory partitions. Contacts, photos and documents will be permanently deleted if you do not take care of this in advance.
Use cloud services or connect the tablet to your computer via a USB cable to copy files. Pay special attention to folders DCIM, Download and Documents. It is also recommended to export the list of installed applications in order to quickly restore the desired environment later.
To carry out the procedure, you will need a high-quality USB cable, preferably an original one, and a computer running Windows, Linux or macOS. Drivers for your device must be installed in advance, otherwise the computer will not see the tablet in debugging or firmware mode.
☑️ Preparing for flashing
Make sure that USB debugging is enabled on the tablet. To do this, go to Settings → About phone and click on the build number seven times to unlock the developer menu. Then activate the item USB debugging in the menu that appears.
Unlocking the bootloader and installing Recovery
The standard bootloader of most manufacturers blocks the installation unsigned system images. To bypass this limitation, you must issue the unlock command. This step often leads to voiding the warranty and completely resetting the device to factory settings.
For devices based on processors Mediatek specific utilities like SP Flash Toolare often used, while for Qualcomm the mode EDLmay be required. A universal method for many models is to use the command via the console:
fastboot oem unlockAfter unlocking, the next step is to install a custom recovery, most often TWRP (Team Win Recovery Project). This is a specialized recovery menu that allows you to install firmware from a memory card or computer, as well as create full system backups (Nandroid backup).
⚠️ Attention: The process of unlocking the bootloader on some devices (for example, Huawei or Honor of old years) may be officially closed by the manufacturer. In such cases, installing Android 7 may not be possible without using paid unlocking services.
The installation of the recovery image is performed through a computer in Fastboot mode. The command looks like this:
fastboot flash recovery twrp_image_name.imgIt is important to prevent an automatic reboot to the standard system immediately after the firmware, since stock Android can overwrite the custom recovery back. Usually, to enter TWRP you need to hold down the combination of buttons Volume up + Power immediately after completing the command.
What to do if TWRP does not start?
If after flashing the tablet starts in stock recovery or cyclically reboots, try flashing the image again without disconnecting the cable. In some cases, the fastboot boot twrp_image_name.img command helps to temporarily launch without writing to memory.
Operating system installation process
When in the TWRP menu, the first thing you need to do is clear the data. Go to the Wipe section and select Advanced Wipe. Check the boxes Dalvik / ART Cache, Cache, System and Data. The section Internal Storage does not need to be cleared if the firmware file is on the internal memory.
Next, go to the menu Install and select the previously downloaded ZIP archive with Android 7 firmware. Swipe the slider at the bottom of the screen to confirm the start of the installation. The process can take from 5 to 20 minutes depending on the speed of the tablet’s flash memory.
Often, along with the system, it is necessary to install a package of services Google Apps (GApps), since they are not available in custom firmware due to licensing restrictions. Select the GApps archive corresponding to the version of Android 7.1 and the architecture of your processor, and install it in the second step without rebooting.
| Component | Purpose | Required |
|---|---|---|
| System Image | Main operating system file | Yes |
| GApps Package | Google Play services, store, maps | Desirable |
| Magisk/SuperSU | Package for obtaining root access | No |
| Drivers/Firmware | Modem and radio drivers (for SIM) | Depends on the model |
After completing the installation of all components, press the button Reboot System. The first launch of a new system always takes longer than usual, as applications are optimized and caches are created. The screen may hang on the logo for up to 10 minutes - this is normal behavior.
If after installation the system boots but constantly crashes, try clearing the Cache partition again directly from the TWRP menu before the first launch. This solves 80% of stability problems.
Solving typical problems and bugs
Custom firmware is rarely perfect. Users often experience that the sound does not work, Wi-Fi turns off on its own, or the battery runs out in a couple of hours. These problems are associated with incompatible kernels or the lack of optimized drivers for the new version Android.
If you notice abnormal energy consumption, check the battery statistics in the settings. Often the culprit is frozen system processes. In such cases, resetting the settings to factory settings (Factory Reset) already inside the new system or flashing the kernel (Kernel) to a more stable version helps.
Lack of Internet access may be a consequence of incorrect configuration of APN access points. Go to your mobile network settings and create a new access point manually, taking the settings from your telecom operator. Sometimes you need to reflash a partition Modem or Radio from stock firmware.
⚠️ Attention: Interfaces and names of menu items may differ depending on the version of TWRP and the specific tablet model. Always check the instructions specifically for your device on the relevant forum.
If the tablet stops turning on and only responds when connected to a PC, you will need to return the stock firmware. To do this, use the manufacturers' official utilities, such as Odin for Samsung or SP Flash Tool for devices on Mediatek.
Most software failures after flashing are resolved by completely formatting the Data section (Format Data), and not by simply deleting files (Wipe). This removes encryption that may conflict with the new system.
Optimization and security after the update
After successfully launching Android 7, it is recommended to immediately disable unnecessary animations to improve the responsiveness of the interface. In the menu for developers, find the items “Window Animation”, “Transition Animation” and set the value 0.5x or disable them completely.
Security on custom firmware is a debatable issue. You don't get monthly security patches like you do on official devices. Therefore, it is not recommended to use such a tablet for online banking or storing critical passwords without additional security measures.
Install a light antivirus and avoid downloading applications from unverified sources. Even though Android 7 still supports many modern apps, some banking customers may refuse to work on rooted devices with an unlocked bootloader.
Is it possible to revert back to an older version of Android?
Yes, it is possible. To do this, you need to download the official stock firmware for your model and install it via Download or Fastboot mode. The procedure will completely return the device to its factory state, including restoring the warranty (if traces of intervention are not visible visually).
Why did the tablet start to heat up after installing Android 7?
This is a common problem when installing a heavier OS on old hardware. The new processor may not be able to handle the background tasks of the new system. Try installing a lightweight kernel or firmware version without unnecessary services (Go Edition or Lite).
Is it safe to enter card data on custom firmware?
No, this is not recommended. An unlocked bootloader and acquired root access violate the integrity of the security system of Android Pay and banking applications. The risk of data interception by malware increases significantly.
Where can I find drivers for my tablet?
Drivers are usually built into firmware utilities (for example, the ADB driver package or SP Flash Tool). You rarely need to download them separately, but if the PC does not see the device, look for “USB Drivers” on the chipset manufacturer’s website.
What is Bootloop and how to get out of it?
Bootloop is a cyclic reboot of the device when it cannot boot the system. Exit is only possible through the Recovery menu: perform a full reset (Wipe Data/Factory Reset). If it does not help, you will need to flash it again.