Q1. My phone's sound is distorted after flashing. Is the Harman Kardon tuning gone?

This stock firmware will restore all original software components, including the specific audio drivers and equalization settings for the Harman Kardon speakers. If the sound is still distorted after a clean flash, it could indicate a hardware problem with one or both of the speakers.

Q2. Why is the flashing tool stuck at "Checking Baudrate"?

This is the most common issue with the SPD Upgrade Tool. It indicates a communication failure, almost always caused by an incorrect driver installation or not using the correct boot key sequence. Re-install the SPD drivers and ensure you are pressing and holding the Volume Down key *before* connecting the USB cable.

Q3. Can I use this firmware to upgrade my Advan G3 Pro to Android 10?

No. This is the official Android 9.0 Pie firmware, which was the final major OS version officially released for the Advan G3 Pro. No official updates to newer Android versions are available for this model.

Advan G3 Pro Stock Firmware (UNISOC SC9863A) .pac File

The Advan G3 Pro is a 6.3-inch budget smartphone from the Indonesian brand Advan, released in 2019. It stood out in its price range with a large HD+ display and a significant audio upgrade, featuring dual speakers tuned by Harman Kardon. If your Advan G3 Pro is bricked, stuck in a bootloop, or experiencing critical software errors, flashing the official stock firmware is the definitive way to restore it to its original factory condition.

Important Note: This device is powered by a UNISOC (formerly Spreadtrum) chipset. The flashing process requires the SPD Upgrade Tool and a `.pac` firmware file. Following this guide will completely erase all your personal data.

⚠️ Prerequisites: Before You Begin

Click Here for the Essential Pre-Flashing Checklist

Backup Your Data: All your files, photos, and contacts on the internal storage will be permanently deleted.
Charge The Battery: To prevent interruptions, ensure the phone’s battery has at least a 50% charge before you begin.
Windows PC & USB Cable: This procedure requires a Windows computer and the phone’s USB Type-C data cable.

📱 Quick Device Specifications

Device: Advan G3 Pro
Release Year: 2019
Chipset: UNISOC SC9863A
Display: 6.3″ HD+ IPS LCD (720×1520)
Battery: 3000 mAh
OS: Android 9.0 Pie
RAM/Storage: 4GB / 64GB
Special Features: Dual Speakers tuned by Harman Kardon, USB Type-C

🛠 Required Tools & Downloads

File / Tool	Download Link
SPD Upgrade Tool	Download Tool
SPD SCI USB Drivers	Download Drivers

⬇️ Advan G3 Pro Stock ROM / Firmware

Model	Android	Chipset	Type	Download	Size
G3 Pro	9.0 Pie	UNISOC SC9863A	SPD (.pac File)	Google Drive	1.4 GB

⚡ Quick Flashing Guide

Download and install the SPD SCI USB Drivers. Extract the firmware (Advan_G3_Pro...SPD.zip) to get the .pac file, and extract the SPD Upgrade Tool.
Launch UpgradeDownload.exe. Click the first gear icon (Load Packet) and select the .pac firmware file you extracted.
Click the third icon, the play button (Start Downloading), to put the tool in standby mode.
Power off your phone completely. Press and hold the Volume Down button.
While still holding the volume button, connect the phone to your PC. The flashing will begin. You can release the button once the progress bar appears.
Wait for the process to finish, indicated by a green “Passed” message. Disconnect the phone and power it on.

For a more detailed, step-by-step walkthrough, please refer to our main guide:
👉 Full Tutorial: How to Flash Firmware with the SPD Upgrade Tool

❓ Frequently Asked Questions (FAQs)

Q1. My phone’s sound is distorted after flashing. Is the Harman Kardon tuning gone?: This stock firmware will restore all original software components, including the specific audio drivers and equalization settings for the Harman Kardon speakers. If the sound is still distorted after a clean flash, it could indicate a hardware problem with one or both of the speakers.
Q2. Why is the flashing tool stuck at “Checking Baudrate”?: This is the most common issue with the SPD Upgrade Tool. It indicates a communication failure, almost always caused by an incorrect driver installation or not using the correct boot key sequence. Re-install the SPD drivers and ensure you are pressing and holding the Volume Down key *before* connecting the USB cable.
Q3. Can I use this firmware to upgrade my Advan G3 Pro to Android 10?: No. This is the official Android 9.0 Pie firmware, which was the final major OS version officially released for the Advan G3 Pro. No official updates to newer Android versions are available for this model.

🔧 Device-Specific Troubleshooting

Phone Not Detected by PC: If drivers are properly installed, the problem is likely the connection method. Ensure the phone is completely powered off. Hold the boot key (Volume Down is standard, but some devices use Volume Up) firmly *before* you plug in the USB cable. You should see a new device appear in your Windows Device Manager.
“Operation Failed” Error During Flashing: If the process starts but then fails, try a different USB port (USB 2.0 is often more reliable) and a known-good data cable. The .pac file could also be corrupted, so downloading the firmware again is a good step. For newer UNISOC chipsets, you may sometimes need a more recent version of the ResearchDownload tool.
Invalid IMEI After Flashing: It is a risk with UNISOC/SPD devices that a full flash can wipe the IMEI numbers. This firmware will not restore them. You will need a separate SPD IMEI repair tool to write your original IMEI numbers (found on the phone’s box or SIM tray) back to the device.
Stuck on Advan Logo After a “Passed” Message: If the flash completes successfully but the phone won’t boot, a factory reset is necessary. Boot into recovery mode (usually by holding Power + Volume Up), and in the menu, select “wipe data/factory reset.” This will clear old data conflicts and allow the new system to boot.