The ZTE Quest 5 (model Z3351S) is a budget-friendly 4G LTE smartphone available on US prepaid carriers like AT&T Prepaid. It’s designed for core functionality and everyday use, featuring a 5.5-inch display and running on a MediaTek (MT6739) processor. This guide provides the official US stock ROM, which is essential for unbricking the device, fixing software bugs, removing a Google FRP lock, or restoring the phone to its original factory state. As a MediaTek device, it requires the SP Flash Tool for a successful installation.
Important: This firmware is specifically for the ZTE Quest 5 (Z3351S). The flashing process for MediaTek devices is very specific. Flashing this on a different model will cause a hard brick. This process will erase all data on your device.
Quick Device Specs
- Device: ZTE Quest 5 (Z3351S)
- Release year: 2019
- Chipset: MediaTek MT6739
- Display: 5.5″ IPS LCD, HD+
- Battery: 2600 mAh
- Original OS: Android 9 Pie
Required Downloads
As a MediaTek device, this phone requires specific tools for flashing.
| File / Tool | Download Link |
|---|---|
| SP Flash Tool | Download Latest Version |
| MediaTek VCOM USB Drivers | Download Drivers |
Stock ROM (Firmware)
| Region / Carrier | Build | Android | Type | Download | Chipset |
|---|---|---|---|---|---|
| USA (AT&T Prepaid) | V1.0.0B33 | 9.0 | SP Flash Tool Firmware | Download | MediaTek |
How to Flash (SP Flash Tool)
This method is for restoring the official stock firmware and will erase all data.
- Install Drivers: Download and extract the MediaTek VCOM drivers. Run the installer. You may need to disable Driver Signature Enforcement in Windows for the drivers to install correctly.
- Extract Tools & Firmware: Extract the SP Flash Tool and the downloaded firmware .zip file into separate folders on your desktop.
- Launch the Tool: Open the SP Flash Tool folder and run flash_tool.exe as an administrator.
- Load Scatter File: In the “Download” tab, click the “Scatter-loading File” button. Navigate to the extracted firmware folder and select the MT6739_Android_scatter.txt file.
- Select Mode: Ensure the dropdown menu is set to Download Only.
- Start Flashing: Power off your phone completely. Click the green Download button in SP Flash Tool, then immediately connect your powered-off phone to the PC with a USB cable.
- Finish: The process will take several minutes. Once a green checkmark appears, the flash is complete. You can disconnect your phone and power it on. The first boot will take longer than usual.
Device-Specific Troubleshooting for ZTE Quest 5
- Correct Driver Installation: The most common failure point is incorrect drivers. You must install the MediaTek VCOM drivers. On modern Windows, this often requires disabling ‘Driver Signature Enforcement’ first. Your PC should recognize the phone as a ‘MediaTek PreLoader USB VCOM Port’ when connected correctly for flashing.
- Using the “Boot Key”: To get the tool to recognize your phone, you must use the boot key. Power the phone off completely. Press and hold the Volume Down button, and while holding it, connect the phone to your PC with the USB cable. Release the button only after the flash process begins.
- Fixing Google FRP Lock: If you are locked out of your phone after a factory reset due to Google’s Factory Reset Protection (FRP), flashing this stock ROM is a common method to remove the lock. The standard flashing process will completely reset the device and the locked account.
- SP Flash Tool Auth/DA Error: Some newer MediaTek devices require a special ‘Download Agent’ (DA) file or an authentication file to flash. If you encounter a security or authentication error in SP Flash Tool, you may need to find a custom DA file specific to the MT6739 chipset or use a different version of the flash tool.
FAQs
Q1. What is a “scatter file”? The scatter file (e.g., MT6739_Android_scatter.txt) is a crucial map for MediaTek firmware. It tells SP Flash Tool the name, size, and location of every partition on the device’s storage, ensuring each part of the software is flashed to the correct place.
Q2. Will this unlock my phone from the AT&T network? No. Flashing the official carrier firmware will restore the phone’s software, but it will not remove the SIM/network lock. The device will still be locked to its original carrier.
Q3. Will this process erase my data? Yes. Flashing the stock ROM with SP Flash Tool will perform a full factory reset and completely wipe all personal data, apps, and settings from your device.
