Q1. The battery on my BQ-4028 UP! drains very fast and the percentage jumps around. Can this fix it?

This is the most widely reported problem for this model. A firmware flash can often fix it by removing software bugs that cause excessive battery consumption. After flashing, it is highly recommended to calibrate the battery: let the phone die completely, then charge it to 100% without interruption. This helps the system relearn the battery's capacity.

Q2. My phone constantly loses its 4G/LTE connection and drops to 3G. Will flashing help?

Yes, this is very likely a software issue with the modem firmware (baseband). Flashing the stock ROM completely reinstalls these critical components, which is a reliable fix for unstable network connections and frequent signal drops.

Q3. The GPS on my phone can't get a location lock. Is it a hardware issue?

Not necessarily. Inaccurate or non-working GPS is another known software bug. Re-flashing the firmware restores the GPS configuration files. After flashing, go to an area with a clear view of the sky, turn on GPS in "High Accuracy" mode, and wait for about 10-15 minutes for the initial satellite lock.

BQ Mobile BQ-4028 UP! Firmware (Stock ROM)

The BQ Mobile BQ-4028 UP! is a compact 4-inch smartphone notable for including 4G LTE connectivity in a small form factor. It runs on Android 6.0 Marshmallow and is powered by a MediaTek MT6735 chipset. Users of this device have reported specific issues over its lifespan, including significant battery drain with an unreliable percentage indicator, frequent loss of 4G network signal, and overheating. Flashing the official stock firmware is a powerful solution that can resolve these software-related bugs by restoring the phone to its original factory state.

ℹ️ Important Note:
This device uses a MediaTek chipset and requires SP Flash Tool to install the firmware. This process will completely erase all data on your phone’s internal storage. Please back up your important files before proceeding.

⚠️ Prerequisites: Before You Begin

Click Here for the Essential Pre-Flashing Checklist

Backup Your Data: All your personal files, contacts, and photos on the device will be permanently deleted.
Charge The Battery: To prevent the phone from shutting down during the process, ensure it has at least a 50% charge.
Windows PC & USB Cable: You will need a Windows computer and the phone’s micro USB data cable.

📱 Quick Device Specifications

Device: BQ Mobile BQ-4028 UP!
Chipset: MediaTek MT6735
Display: 4.0″ TFT (800×480)
Operating System: Android 6.0 Marshmallow
RAM: 1GB
Storage: 8GB
Battery: 2000 mAh

🛠 Required Tools & Downloads

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

⬇️ BQ Mobile BQ-4028 UP! Stock ROM / Firmware

Android Version	Build Number	Chipset	Download Link
6.0 Marshmallow	V04_220224	MediaTek MT6735	Download (MediaFire)

⚡ Quick Flashing Guide

Download and install the MediaTek VCOM drivers. Extract the firmware ZIP (BQ_Mobile_BQ-4028...zip) and the SP Flash Tool on your PC.
Launch flash_tool.exe. Click the “Scatter-loading” button and select the MT6735_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.
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 battery on my BQ-4028 UP! drains very fast and the percentage jumps around. Can this fix it?: This is the most widely reported problem for this model. A firmware flash can often fix it by removing software bugs that cause excessive battery consumption. After flashing, it is highly recommended to calibrate the battery: let the phone die completely, then charge it to 100% without interruption. This helps the system relearn the battery’s capacity.
Q2. My phone constantly loses its 4G/LTE connection and drops to 3G. Will flashing help?: Yes, this is very likely a software issue with the modem firmware (baseband). Flashing the stock ROM completely reinstalls these critical components, which is a reliable fix for unstable network connections and frequent signal drops.
Q3. The GPS on my phone can’t get a location lock. Is it a hardware issue?: Not necessarily. Inaccurate or non-working GPS is another known software bug. Re-flashing the firmware restores the GPS configuration files. After flashing, go to an area with a clear view of the sky, turn on GPS in “High Accuracy” mode, and wait for about 10-15 minutes for the initial satellite lock.

🔧 Device Troubleshooting

The phone gets excessively hot: This is another common complaint. A clean firmware installation will eliminate any rogue background processes that might be forcing the CPU to run at high speeds, which is a primary cause of software-related overheating. If the issue persists after flashing, avoid heavy multitasking.
SP Flash Tool gives a BROM ERROR: This is a driver or connection error. Ensure you have properly installed the MediaTek VCOM drivers (you may need to disable driver signature enforcement in Windows). Use a high-quality USB cable and a main USB port on your PC. Sometimes, holding down Volume Up or Volume Down while connecting the phone can help establish the connection.
Stuck in a bootloop after a successful flash: Let the phone try to boot for at least 10 minutes. If it’s still stuck, you will need to perform a factory reset. Turn the phone off, then boot into recovery mode (usually Power + Volume Up). From the menu, select “Wipe data/factory reset” and “Wipe cache partition,” then reboot.