ZTE Axon 20 4G (A2121G) Firmware Flash File Download [Stock Rom]
This firmware is for the ZTE Axon 20 4G (model A2121G), the 4G variant of the innovative Axon 20 series. For users who need to resolve critical software errors, fix a device stuck in a bootloop, or perform a full factory restore, flashing the official stock firmware is the most reliable solution.
Important Note: The filename for this package is incorrectly labeled with “QPST.” The ZTE Axon 20 4G is powered by a UNISOC T618 chipset, not a Qualcomm chip. Therefore, the correct restoration process requires the SPD Upgrade Tool, not QFIL. Following the correct guide for the device’s actual hardware is essential.
Quick Device Specs
- Device
- ZTE Axon 20 4G (A2121G)
- Release year
- 2021
- Chipset
- UNISOC T618
- Display
- 6.92″ OLED, FHD+ (2460×1080)
- Battery
- 4220 mAh (Non-removable)
- Memory
- 6GB RAM + 128GB storage
- Camera
- 64MP + 8MP + 2MP + 2MP quad rear, 32MP front
- OS
- Android 10
- Region
- Global / Europe / Canada
Required Downloads
File / Tool | Download Link |
---|---|
SPD Upgrade Tool | Download Tool |
SPD/UNISOC USB Drivers | Download Drivers |
Stock ROM & Firmware
Version | Android | Region | Type | Download | Size |
---|---|---|---|---|---|
V1.0.0B07 | 10 | Global / EU / Canada | SPD / PAC | Download | ~2.4 GB |
Quick Flashing Guide
- Download and install the SPD USB Drivers and the SPD Upgrade Tool on your computer.
- Extract the downloaded firmware ZIP file to get the firmware package with a `.pac` extension.
- Launch the SPD Upgrade Tool, click the first gear icon to “Load Packet,” and select the `.pac` file.
- Power off your phone, then press and hold the Volume Down button while connecting it to your PC to start the flashing process.
For a complete, step-by-step tutorial with screenshots, please refer to our definitive guide:
How to Flash Firmware with the SPD Upgrade Tool
FAQs
Q1. Is this for the famous Axon 20 5G with the under-display camera?
No. This firmware is strictly for the Axon 20 4G (A2121G), which uses a UNISOC chipset and has a standard front-facing camera in a teardrop notch. The Axon 20 5G is a different device with a Qualcomm chipset and its own specific firmware.
Q2. Why does the filename say “QPST” but the guide uses the SPD Tool?
The original uploader of the file made a mistake in the filename. The ZTE Axon 20 4G is confirmed to use a UNISOC T618 chipset, which is only compatible with the SPD Upgrade Tool. Using the correct tool for the phone’s actual hardware is essential for a successful flash.
Q3. What is a `.pac` file?
A `.pac` file is a compressed firmware archive used for devices with UNISOC (formerly Spreadtrum) chipsets. It contains all the phone’s software partitions (like system, boot, recovery, etc.) bundled into a single file, allowing the SPD Upgrade Tool to flash the entire system at once.
Q4. The tool is stuck on “Checking Baudrate.” What should I do?
This is a common connection error. It is usually caused by improperly installed drivers, a faulty USB cable, or not holding the correct boot key (Volume Down) when connecting the device.
Troubleshooting (ZTE Axon 20 4G)
- PC Not Detecting Phone: This is almost always a driver issue. Ensure the SPD drivers are correctly installed. You may need to disable Driver Signature Enforcement in Windows. Also, try a different USB port and cable.
- Device Stuck on Boot Logo: The first boot after flashing can take up to 15 minutes. If it is still stuck, you will need to boot into recovery mode (usually by holding Volume Up + Power from off) and perform a “Wipe data/factory reset”.
- Flashing Fails Midway: This can be caused by a loose USB connection or a corrupted download. Ensure the cable is secure. If it fails again, re-download the firmware file.
- Network Issues After Flashing: While this appears to be a general international firmware, flashing it on a device from a very different region or carrier could potentially lead to network band incompatibilities.