Q1. The portrait mode (bokeh effect) on my front or back camera doesn't work. Can this be fixed?

Yes, this is the most common software complaint for the Twin Pro. These issues are typically caused by corrupted camera drivers or bugs in the camera application. Flashing the official stock firmware is the most reliable way to restore all camera functions, including the portrait mode effect on both the front and rear cameras.

Q2. My Face Unlock and fingerprint sensor are very unreliable. What can I do?

This is often a software calibration issue. Reinstalling the firmware restores the original drivers for both the fingerprint sensor and the camera used for Face Unlock. After flashing, be sure to delete your old biometric data and re-register your face and fingerprints for improved accuracy.

Q3. The phone gets very hot when using the camera or playing games. Is this normal?

While some warmth is expected, excessive heat is often made worse by software inefficiencies. A clean firmware flash can help by closing rogue background processes and restoring the phone's intended power management, which can reduce software-related overheating during heavy use.

BQ Mobile BQ-5517L Twin Pro Firmware (Stock ROM)

The BQ Mobile BQ-5517L Twin Pro is a mid-range smartphone from 2018 that was marketed heavily on its quad-camera setup, featuring dual cameras on both the front and back. Running on Android 8.1 Oreo and powered by a MediaTek MT6750 chipset, it was designed for users focused on photography. However, the device is known for specific software-related issues that can undermine its key features. Users frequently report problems with the camera app, such as a non-functional portrait mode (bokeh), an unreliable Face Unlock feature, and significant overheating during use. Flashing the official stock firmware is the most effective method to resolve these bugs and restore the phone’s camera and biometric systems.

ℹ️ Important Note:
This phone is powered by a MediaTek chipset and requires the SP Flash Tool to install the firmware. This process will completely erase all your personal data. Ensure you have backed up your important files before you begin.

⚠️ Prerequisites: Before You Begin

Click Here for the Essential Pre-Flashing Checklist

Backup Your Data: All your contacts, photos, and files on the phone’s internal storage will be permanently wiped.
Charge The Battery: To prevent the phone from shutting down during the update, ensure the battery is charged to at least 50%.
Windows PC & USB Cable: You will need a Windows computer and a standard micro USB cable to perform the flash.

📱 Quick Device Specifications

Device: BQ Mobile BQ-5517L Twin Pro
Chipset: MediaTek MT6750
Display: 5.5″ HD+ IPS (1440×720)
Operating System: Android 8.1 Oreo
RAM: 3GB
Storage: 32GB
Battery: 3080 mAh

🛠 Required Tools & Downloads

File / Tool	Download Link
SP Flash Tool	Download Tool
MediaTek USB VCOM Drivers	Download Drivers

⬇️ BQ Mobile BQ-5517L Twin Pro Stock ROM / Firmware

Android Version	Build Number	Chipset	Download Link
8.1 Oreo	OS4.0_E_20180623	MediaTek MT6750	Download (Google Drive)

Quick Steps to Flash BQ-5517L Twin Pro Firmware

Download and install the MediaTek VCOM drivers. Extract the firmware ZIP file (BQ_Mobile_BQ-5517L_..._8.1.zip) and the SP Flash Tool on your PC.
Launch flash_tool.exe. Click the “Scatter-loading” button and select the MT6750_Android_scatter.txt file from the extracted firmware folder.
Ensure the flashing mode in the dropdown menu is set to “Download Only.”
Power off your phone completely. Click the green “Download” button in SP Flash Tool, then immediately connect the powered-off phone to your PC via USB cable.
The flash will start automatically. Once you see the green checkmark pop-up, you can disconnect the phone and power it on.

For a more detailed, step-by-step guide on this process, please refer to our main tutorial:
👉 Full Tutorial: How to Flash MediaTek Firmware with SP Flash Tool

❓ Frequently Asked Questions (FAQs)

Q1. The portrait mode (bokeh effect) on my front or back camera doesn’t work. Can this be fixed?: Yes, this is the most common software complaint for the Twin Pro. These issues are typically caused by corrupted camera drivers or bugs in the camera application. Flashing the official stock firmware is the most reliable way to restore all camera functions, including the portrait mode effect on both the front and rear cameras.
Q2. My Face Unlock and fingerprint sensor are very unreliable. What can I do?: This is often a software calibration issue. Reinstalling the firmware restores the original drivers for both the fingerprint sensor and the camera used for Face Unlock. After flashing, be sure to delete your old biometric data and re-register your face and fingerprints for improved accuracy.
Q3. The phone gets very hot when using the camera or playing games. Is this normal?: While some warmth is expected, excessive heat is often made worse by software inefficiencies. A clean firmware flash can help by closing rogue background processes and restoring the phone’s intended power management, which can reduce software-related overheating during heavy use.

🔧 Device Troubleshooting

I get a “PMT changed for the ROM” error in SP Flash Tool: This error means the partition layout on the phone is different from the one in the firmware file. To fix this, change the flashing mode in SP Flash Tool from “Download Only” to “Firmware Upgrade” and try again. This will reformat the partitions to match the firmware.
SP Flash Tool shows a BROM ERROR or the phone is not detected: This is a driver issue. Ensure the MediaTek VCOM drivers are correctly installed (you may need to disable Windows Driver Signature Enforcement). Use a good quality USB cable and a main USB port on your PC. Make sure the phone is completely powered off before connecting it.
The phone is stuck in a bootloop after a successful flash: The first boot can be slow. If it is still stuck after 15 minutes, you need to clear old data. Boot into recovery mode (Power + Volume Up), use the volume buttons to select “Wipe data/factory reset,” and confirm. This will allow the phone to boot properly.