ZTE a1 (ZTG01) Firmware Flash File Download [Stock Rom]
The ZTE a1 (model ZTG01) is a 5G-capable smartphone equipped with the powerful Snapdragon 765G chipset, released exclusively for the au by KDDI carrier in Japan. If your device is stuck on the au logo, experiencing critical software errors, or is completely bricked, flashing the official stock firmware is the definitive method to restore it to its original factory condition.
Important Note: This device runs on a Qualcomm Snapdragon 765G chipset. The flashing process requires the device to be in EDL Mode and utilizes the QFIL (Qualcomm Flash Image Loader) tool. This firmware is the official software for the Japanese au/KDDI carrier and will restore all original apps and the network lock.
Quick Device Specs
- Device: ZTE a1 (ZTG01)
- Release year: 2020
- Chipset: Qualcomm Snapdragon 765G 5G
- Display: 6.5″ OLED, 2340×1080
- Battery: 4000 mAh (Non-removable)
- Memory: 6GB RAM + 128GB storage
- Camera: 48MP + 8MP + 2MP + ToF 3D quad rear, 32MP front
- OS: Android 10
- Carrier: au by KDDI (Japan)
Required Downloads
| File / Tool | Download Link |
|---|---|
| QPST (QFIL) Tool | Download QPST Tool |
| Qualcomm USB Drivers | Download Drivers |
Stock ROM & Firmware
| Version | Android | Carrier | Type | Download | Size |
|---|---|---|---|---|---|
| V1.0.0B25 | 10 | au by KDDI (Japan) | QPST | Download | ~2.8 GB |
How to Flash Using QFIL
- Install Drivers: Download and install the Qualcomm HS-USB QDLoader drivers on your PC. You may need to disable Driver Signature Enforcement in Windows to ensure they install correctly.
- Extract Files: Unzip the downloaded Firmware package into a folder. You will see multiple files, including a programmer file like prog_firehose_…mbn. Also, extract the QPST tool.
- Launch QFIL: Navigate to the QPST installation folder (usually in C:\Program Files (x86)\Qualcomm\QPST\bin) and run QFIL.exe.
- Enter EDL Mode: Power off your ZTE a1 completely. Press and hold both the Volume Up + Volume Down buttons simultaneously. While holding them, connect the phone to your computer with a USB-C cable. The screen will remain black.
- Configure QFIL:
- The top of QFIL should now show “Qualcomm HS-USB QDLoader 9008”. If not, check your drivers.
- Select Flat Build as the build type.
- Click “Browse…” next to Programmer Path and select the prog_firehose_… file from your firmware folder.
- Click “Load XML…” and select the rawprogram_unsparse.xml (or similar name), followed by the patch0.xml file.
- Begin Flashing: Click the blue “Download” button. The flashing process will begin, and you will see progress in the status bar. Do not disconnect the device.
- Wait for Completion: The process is finished when the status log shows “Download Succeeded.”
- Reboot: Disconnect the phone and press and hold the Power button until it vibrates and starts to boot. The first boot can take up to 15 minutes.
FAQs
Q1. Can I use this firmware on a non-Japanese phone or a different carrier?
No. This firmware is specifically for the ZTE a1 (ZTG01) model sold by au/KDDI in Japan. It is carrier-locked and contains software and modem configurations specific to their network. Flashing it on another model will result in a bricked device.
Q2. Will this process remove the KDDI SIM lock?
No, it will not. This is the official carrier firmware, and flashing it will restore all original software, including the network lock. The device will remain locked to the au by KDDI network.
Q3. The phone boots into Japanese. How do I change the language?
During the initial setup wizard, you will be prompted to select a language. Look for a globe icon or the word 言語 (Gengo). If you miss this, you can go to 設定 (Settei – Settings) > システム (Shisutemu – System) > 言語と入力 (Gengo to nyūryoku – Language & input) to change it to English.
Q4. What is EDL Mode and why is it necessary?
EDL (Emergency Download) Mode is a low-level recovery state for Qualcomm devices. It allows QFIL to communicate directly with the phone’s storage, bypassing the Android operating system. This is crucial for “unbricking” a device that is stuck in a bootloop or will not power on normally.
Troubleshooting (ZTE a1 ZTG01)
- QFIL shows “No Port Available”: This is a driver issue. Ensure the Qualcomm 9008 drivers are installed correctly (check Windows Device Manager). Try a different USB port and a high-quality USB-C cable.
- “Sahara” or “Firehose” Error in QFIL: This error indicates a failure to communicate with the phone’s memory. It can be caused by incorrect drivers, a bad USB connection, or selecting the wrong programmer (.mbn) file. Ensure you are using the files from the provided firmware package.
- “Invalid SIM” or No Service in Japan: After flashing, the phone must be activated with an au by KDDI SIM card. It will not work with other Japanese carriers like Docomo or SoftBank without an official unlock.
- KDDI apps are not working: Many Japanese carrier apps require an active connection to the KDDI network and may need to be updated after the first boot. Connect to Wi-Fi and allow the phone to idle for a while to complete background setups.
