Vivo Y66i (PD1621B) Firmware Flash File Download [Stock Rom]

Important Safety Notice

• Backup Your Data: This process will completely erase all data on your phone.
• Use the Right Files: The firmware must be an exact match for your device model (PD1621B). Flashing the wrong firmware can permanently brick your phone.
• EDL Mode is Crucial: The phone must be in Emergency Download (EDL) mode for QPST to work. This is a low-level boot mode that bypasses the operating system. Getting into EDL mode can be tricky and may require a test point on the phone’s motherboard.

Prerequisites: All Necessary Files and Tools

1. A Windows PC: QPST and QFIL are Windows-based tools.
2. USB Cable: Use a high-quality USB data cable.
3. QPST Package: Download and install the complete QPST package. This usually includes QFIL.
4. Qualcomm USB Drivers: Install the correct Qualcomm QDLoader USB drivers on your PC. You might need to disable Windows Driver Signature Enforcement to install them.
5. Vivo Y66i Firmware: The Vivo Y66 (PD1621) Flash after repair Convert to Global Tested Firmware.rar file.
6. QPST/QFIL Authentication Bypass Tool (Optional but Recommended): Newer Vivo devices may require a tool to bypass the authentication process for flashing. This is often an executable program that runs alongside QFIL.

Detailed Step-by-Step Instructions

Step 1: Prepare Your PC and Files

1. Extract the Firmware: Unzip the Vivo Y66 (PD1621) Flash after repair Convert to Global Tested Firmware.rar file. This will give you a folder containing various files, including the raw program and patch XML files (rawprogram0.xml, patch0.xml), and the programmer file (prog_emmc_firehose.mbn or similar). These are the key files for QFIL.
2. Install Drivers: Install the Qualcomm QDLoader drivers. This is a critical step. If your PC doesn’t recognize the phone in EDL mode, the flashing will fail.
3. Install QPST: Run the QPST installer on your PC. After installation, you will find the QFIL application in the C:\Program Files\Qualcomm\QPST\bin folder or by searching for it in the Start Menu.

Step 2: Enter Emergency Download (EDL) Mode

This is the most difficult and critical part of the process. The standard methods might not work.

• Method A (Commonly Used):
  1. Power off the Vivo Y66i completely.
  2. Press and hold both the Volume Up and Volume Down buttons simultaneously.
  3. While holding the buttons, connect the phone to your PC via the USB cable.
  4. Your PC should make a sound indicating a new device has been connected. In Device Manager, it should appear under “Ports (COM & LPT)” as “Qualcomm HS-USB QDLoader 9008.” If it appears as “Qualcomm HS-USB Diagnostics 900E” or something else, it is not in EDL mode.
• Method B (If Method A Fails):
  • This may require finding a “test point” on the phone’s motherboard. A test point is a specific pair of pins that, when shorted with tweezers, force the phone into EDL mode. This method should only be attempted if you are experienced in phone repair as it can damage your device.

Step 3: Flash the Firmware with QFIL

1. Launch QFIL: Open the QFIL application from your Start Menu or the QPST folder as an administrator.
2. Connect Device: Make sure your phone is in EDL mode and connected. The QFIL window should display “Qualcomm HS-USB QDLoader 9008” in the top bar. If it shows “No Port Available,” your phone is not in EDL mode.
3. Select the Programmer: In the QFIL window, under the “Select Programmer” section, click “Browse”. Navigate to the folder where you extracted the firmware and select the programmer file, which is typically prog_emmc_firehose.mbn or a similar .mbn file.
4. Load the XML Files:
   • Click “Load XML”.
   • A dialog box will appear. First, select the rawprogram0.xml file.
   • Immediately after, another dialog will pop up. Select the patch0.xml file.
5. Start the Flash:
   • Ensure all settings are correct.
   • Click the “Download” button.
   • The flashing process will begin. You will see a progress bar and log messages in the QFIL window. Do not touch the phone or the USB cable during this time.
6. Completion:
   • The process can take several minutes.
   • When it’s complete, the log will show “Download Succeed” and the progress bar will turn green.
   • You can now safely disconnect the phone.

Step 4: Reboot Your Phone

1. Reboot: After the flash is successful and the phone is disconnected, press and hold the Power button for about 10-15 seconds to force it to reboot.
2. First Boot: The phone will reboot and begin its first boot-up on the new firmware. This may take longer than a normal boot.
3. Initial Setup: You will be taken to the Android initial setup screen. Complete the setup to start using your phone.