Asus Zenfone 3s Max ZC521TL Firmware Flash File (Stock ROM Collection)

Today we have the latest stock ROM flash file for the Asus Zenfone 3s Max ZC521TL powered by a Mediatek MT6750 processor. To install the firmware flash file, we need a software called the SP Flash tool which can be helpful to flash the stock ROM on your device. The method is simple and easy. We have also added video and step-by-step tutorials to make things easier to flash the official flash file.

This process is helpful if you have bricked your device, lag, or shuttering performance, to fix Bluetooth and WiFi issues, to unroot or bypass the FRP lock. So without further wasting our time, let’s understand what is stock firmware flash file.

Asus Zenfone 3s Max ZC521TL Firmware Flash File (Stock ROM Collection)

Asus Zenfone 3s Max: Device Overview

Asus Zenfone 3s Max features a 5.2-inches display with a screen resolution of 720 x 1280 pixels. The smartphone is powered by an Octa-core 1.5 GHz Cortex-A53 and Mediatek MT6750 processor coupled with 3GB of RAM. The phone packs 32GB internal memory which can also be expanded up to 256GB via microSD card. The camera on the Asus Zenfone 3s Max comes with a 13MP rear camera with f/2.0, autofocus, dual-LED (dual tone) flash, and an 8MP front shooting camera.

Asus Zenfone 3s Max runs on Android 7.0 Nougat out of the box and a Non-removable Li-Po 5000 mAh battery. It also has a fingerprint sensor in the front The handset supports a dual sim with 4G on both slots. It comes with connectivity options such as Bluetooth, Wifi, USB OTG, 3G, and 4G.

Advantages of Stock ROM:

Here are the answers to why you need to download and save the Asus Zenfone 3s Max Stock ROM flash file on your computer.

  • If your device is dead, you can unbrick using the Stock ROM file
  • You can fix or repair the IMEI on your device using DB files from Stock ROM
  • Remove any malware or Adwares from Zenfone 3s Max
  • You can fix the boot loop issue on Zenfone 3s Max
  • Fix Unfortunately, the app has stopped errors on Zenfone 3s Max
  • Fix Network related issue
  • Patch Boot image to Root using Magisk
  • You can unroot Zenfone 3s Max
  • To Reset or Remove FRP on your device
  • Restore Zenfone 3s Max back to Factory State

Firmware Details:

  • Device Name: Asus Zenfone 3s Max ZC521TL
  • ROM Type: Stock ROM
  • Gapps File: Included
  • Tool Supported: SP Flash tool
  • Processor: Mediatek MT6750
  • Android Version: Android 7.0 Nougat

How to Install Asus Zenfone 3s Max ZC521TL Flash File

Before installing the Stock ROM on your Asus Zenfone 3s Max, you should download the firmware flash file. Then download and install the USB Drivers and flash tool on the PC as well. Once you’re done with these, you can proceed to the steps below. But let’s take a quick look at the Stock Firmware importance and firmware details below.


Download Flash Files

Firmware Detail Download Link
Flash File Name: ZC521TL_MT6750_14.02.1709.15_IN_20171123
File Size: 2 GB
File Type: SP Flash Tool Image
Android Version: Android 7.0 Nougat

Method 1: Instructions to Install via Recovery:

  1. Download the latest firmware from the above update tracker section (if available).
  2. Turn off your phone and enter the recovery mode by pressing the Power button +Volume UP button.
  3. Once you have booted into the recovery mode, select apply update from sd card.
  4. Locate the firmware file on your phone’s internal or external storage and select it.
  5. The installation will begin.
  6. Once the process is completed, your phone will reboot to put things into place.
  7. That’s it!

Methods 2: Install RAW Firmware zip file:

Suppose you have downloaded the RAW firmware zip file, then you can follow this method 2 to install the firmware on your Asus Zenfone 3s Max ZC521TL.

  1. First of all, download the Asus Zenfone 3s Max ZC521TL RAW firmware zip file and extract it on your PC.
  2. Open the extracted folder and it should contain the flashing script, full RAW firmware files, and Android Tools.
  3. Turn off your Asus Zenfone 3s Max.
  4. Enter the fastboot mode by pressing and holding the Volume Up and Power keys simultaneously.
  5. Once your phone is powered off, hold the Volume Up and Power keys together to enter Fastboot Mode.
  6. Connect your phone to the PC using the USB cable.
  7. Look for the ‘flashall_AFT.cmd‘ file and double click on it to launch the flashing script.
  8. When the script started reading in the command prompt (CMD) window, you have to wait until the process gets completed.
  9. Once the installation is completed, your device will reboot automatically to the new update.

Methods 3: Flash Via SP Flash Tool

  1. Make sure you follow and download all the required files and flash tools on your PC.
  2. Open the flash tool exe file to open the SP Flash Tool User InterfaceSP Flash Tool Folder
  3. Once your load the SP Flash tool UI, Tap on the Download option
    SP Flash Tool Screen
  4. In the download tab, you have to load both the download agent and the scatter text file in the scatter-loading section.
  5. You will find the scatter text file inside the ROM package for most cases, if not, you can create a scatter text file on your own.
  6. Once you load the file, click the Download buttonSP Flash Tool Download Button
  7. To start the upgrade process of stock ROM on your Asus Zenfone 3s Max ZC521TL, you need to turn off your device and hold the Volume Down and Volume Up key together and Connect your Phone to PC/Laptop using USB Cable (Keep the Volume Down and Volume Up button until your computer detects the phone.)
  8. When the phone connects, your device will start upgrading the stock firmware
  9. You need to wait for a few minutes to complete the upgrade process.
  10. Once the flashing process completes, you will find a green button which means a successful upgrade. sp green ring
  11. That’s it! You can reboot your Asus Zenfone 3s Max ZC521TL

Follow our full-depth video guide below:

Video Guide to Install Stock ROM via SP Flash Tool


That’s it, guys. We hope that you’ve installed the Stock Firmware on your Asus Zenfone 3s Max device successfully. Feel free to ask in the comments below for any queries.

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