If your Cubot R11 is stuck on the startup logo (bootloop), experiencing frustratingly slow charging, showing an “Invalid IMEI” error, or suffering from constant app crashes, flashing the official stock firmware is the definitive solution. This guide provides the official Android 8.1 firmware package and instructions to completely restore your device’s software and resolve these critical issues.
🚨 Critical Pre-Flash Warning
Flashing will permanently erase all data from your Cubot R11’s internal storage, including photos, apps, and contacts. Please ensure you have backed up your important files. Furthermore, using the incorrect flashing mode (e.g., “Format All”) in SP Flash Tool can wipe your phone’s unique IMEI numbers, leading to a loss of network connectivity. Follow the instructions carefully.
Device Specifications Verification
Confirm these specifications match your device before flashing:
| Specification | Details |
|---|---|
| Device Name | Cubot R11 |
| Release Date | June 2018 |
| Chipset | MediaTek MT6580 (28nm, Quad-Core 1.3GHz Cortex-A7) |
| GPU | ARM Mali-400 MP2 |
| Display | 5.5″ IPS LCD, 720 x 1440 pixels (HD+), 18:9 ratio |
| RAM/Storage | 2GB RAM / 16GB internal storage |
| Battery | 2800mAh removable Li-Ion |
| Android Version | Android 8.1 Oreo |
| Key Features | Dual Rear Camera (8MP primary sensor interpolated to 13MP), 5MP front camera (interpolated to 8MP), Removable Battery |
Official Firmware Download
| Filename | Date | Region | Android | Size | Download Link |
|---|---|---|---|---|---|
| Cubot_R11_MT6580_20180313_8.1.0.zip | Mar 2018 | Global | 8.1 | 885MB | Download (MediaFire) |
Note: This is the stable launch firmware for the device, designed to restore it to its original factory condition.
Required Tools & Drivers
- SP Flash Tool (latest version)
- MediaTek VCOM USB Drivers
- The Cubot R11 firmware package (from the table above)
Driver Installation Notes:
- Properly install the MediaTek VCOM drivers before you connect your phone.
- On Windows 10/11, you may need to disable driver signature enforcement for a successful installation.
Quick Cubot R11 Firmware Flashing Instructions
- Download and extract the Cubot R11 firmware and SP Flash Tool archives on your computer.
- Run `flash_tool.exe` and load the `MT6580_Android_scatter.txt` file from the firmware folder into the “Scatter-loading File” field.
- Ensure the dropdown menu is set to “Download Only.” This is crucial to protect your IMEI number.
- Click the green “Download” button. Now, power off your Cubot R11 completely (you can remove and re-insert the battery to be sure).
- Connect your powered-off phone to the PC with a USB cable. The flashing process will start automatically, and a pop-up with a green checkmark will confirm when it’s finished.
For a more detailed guide covering common errors and driver setup, visit our complete tutorial: How to Flash Firmware on MediaTek (MTK) Smartphones.
Troubleshooting & Optimization Guide
1. Fixing Bootloop (Stuck on Cubot Logo)
- Symptoms: The phone turns on but never gets past the animated Cubot logo screen.
- Flashing the stock firmware using the “Download Only” mode will completely overwrite the damaged system partition.
- This process replaces all core OS files with fresh, official ones, which resolves the bootloop and allows the phone to boot up normally.
2. Restoring Invalid IMEI and Network Signal
- Symptoms: You see no network bars, an “Invalid IMEI” message appears in settings or when dialing `*#06#`, and you cannot make or receive calls.
- Prevention is key: ALWAYS use “Download Only” mode.
- If the IMEI is already lost, the first step is to re-flash the stock firmware using the correct “Download Only” mode. This can sometimes restore the NVRAM partition.
- If the IMEI remains null after flashing, it requires advanced tools like Maui META to manually rewrite the numbers. This is a complex procedure; we strongly advise preventing the issue in the first place.
3. Solving Slow Charging or “Not Charging” Issues
- Symptoms: The battery charges extremely slowly (taking over 6-8 hours for a full charge), or the percentage doesn’t increase at all when plugged in.
- Check Hardware First: Use a different, known-good USB cable and charger (rated 5V/1A). Clean any dust from the phone’s micro-USB port with a non-metallic tool.
- Clean Battery Contacts: Since the battery is removable, power off the phone, take out the battery, and gently clean the golden contact points on both the battery and the phone with a soft, dry cloth or a pencil eraser.
- Flash the Firmware: If hardware checks out, a software glitch might be preventing the phone from charging correctly. Flashing the stock ROM resets the charging drivers and power management system, which can fix the problem.
4. Repairing Google Play Store and Services Errors
- Symptoms: You constantly see errors like “Google Play Services has stopped,” or you’re unable to download or update apps from the Play Store.
- Flashing the firmware reinstalls the entire Google framework, fixing any corruption that caused the errors.
- After flashing, ensure you have at least 1GB of free internal storage, as low space can also cause Play Store issues.
Frequently Asked Questions
- Why does my camera say 13MP, but the photos look grainy?
- The Cubot R11 uses a technique called software interpolation. The main camera sensor is physically 8 megapixels, and the phone’s software enlarges the image to 13 megapixels. This process can result in a loss of detail and sharpness. Flashing the firmware restores the stock camera app but cannot change the hardware’s capabilities.
- Can I upgrade my Cubot R11 to Android 9 or 10?
- No. Android 8.1 Oreo is the final and only official version released for the Cubot R11. The MediaTek MT6580 chipset does not support official upgrades to newer Android versions.
- Is it safe to use the “Format All + Download” option in SP Flash Tool?
- No, you should almost never use it. This option erases all partitions, including the critical NVRAM partition that stores your IMEI number. Stick to “Download Only” for safety.
- My phone is not detected by the PC. What should I do?
- This is a driver issue. Ensure you have disabled driver signature enforcement on Windows and installed the VCOM drivers correctly. Try a different USB port and cable. If the battery is completely dead, let it charge for at least 30 minutes before attempting to flash.
Conclusion
Flashing the official Android 8.1 stock firmware on your Cubot R11 is the most powerful method for resolving severe software malfunctions. Whether you’re dealing with a persistent bootloop, a lost network signal due to an invalid IMEI, or frustrating charging problems, this process provides a clean slate and restores your device to its original, stable condition.
Did you successfully revive your device? Let us know your experience in the comments section below to help others in the community!
