Here you can download the latest official Stock ROM (Firmware) files for the Stock rom unbrick for Asus Zenfone 3s Max ZC521TL. These files are essential for repairing software issues, fixing bootloops, upgrading/downgrading the OS, or restoring your device to its factory state.
| Display | 5.2-inch HD IPS LCD, 720×1280 pixels, 2.5D curved glass, 450 nits |
| Processor | MediaTek MT6750 Octa-core (4x 1.5 GHz Cortex-A53 & 4x 1.0 GHz Cortex-A53), Mali-T860 MP2 GPU |
| Memory | 3GB RAM / 32GB or 64GB ROM (expandable up to 2TB) |
| Operating System | Android 7.0 Nougat, ZenUI 3.0 |
| Battery | 5000 mAh Li-Po, No fast charging |
Prerequisites & Preparation
- Backup Data: Flashing will completely wipe all data on your device. Back up important files and settings before proceeding.
- Battery Level: Ensure your device has at least 50% battery to prevent shutdown during the flashing process.
- USB Driver & Tools: Install the correct USB drivers for your brand and prepare the flashing tool (Odin for Samsung, SP Flash Tool/QPST for Qualcomm/MTK, etc.).
CAUTION: Flashing official firmware carries a risk of bricking your device. Proceed with caution and at your own risk. addROM is not responsible for any damage caused to your device.
Download Stock ROM & Firmware
Global / General
| File Type | Firmware / Build | Region / Model | OS Version | Download Link |
|---|---|---|---|---|
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
| Stock ROM | X00G | Global / General | – | Google Drive | OneDrive | Google Drive |
How to Flash Firmware / Stock ROM
To flash the stock firmware on your Asus device using SP Flash Tool, follow these steps:
- Download and install the MTK USB Drivers on your computer.
- Download and extract the SP Flash Tool.
- Launch
Flash_tool.exeas administrator. - Click on the Scatter-loading button and select the Android scatter file (
.txt) from the extracted firmware folder. - Click the Download button.
- Power off your device completely, hold the Volume Down or Volume Up button, and connect it to the computer via USB cable.
- The flashing process will start automatically. Wait for the green “Download OK” checkmark to appear.
