Realme 1 CPH1859 Firmware Download Not Completed Error Fix – Oppo_Custom.bin Solution

If you’re flashing Realme 1 CPH1859 using SP Flash Tool or DownloadTool, and the process stops with an error like “Download not completed” or “Oppo_Custom.bin missing”, you’re not alone. This issue is common on MTK-based Realme and Oppo devices, especially when using modified or incomplete firmware packages.

Why the “Download Not Completed” Error Occurs

This issue usually happens when the Oppo_Custom.bin file is missing or corrupted in the firmware package. The file is part of the custom partition that controls specific security and display configurations.
Here are the most common causes:

• Firmware package is incomplete or not properly extracted
• Oppo_Custom.bin file is missing or damaged
• Using wrong DownloadTool or DA/Auth files
• Secure boot issue (especially in Android 9 and above)

Step-by-Step Solution to Fix Oppo_Custom.bin Error

Step 1: Use a Verified Firmware Package

Download the official firmware for Realme 1 CPH1859 from a trusted source like MobiFirms.com.
Make sure the archive includes:

If the file is missing, re-download or use a fixed firmware version that already includes the Oppo_Custom.bin patch.

Step 2: Install Latest MTK Drivers

Uninstall old drivers and install MTK USB VCOM drivers.

• Disable driver signature enforcement (on Windows 10/11).
• Use “Device Manager” to confirm the driver is installed properly.

Step 3: Use the Correct Flash Tool

For MTK-based Realme 1 devices:

Load the scatter file → Check all partitions → Uncheck “userdata” (to keep data safe if needed) → Click Download.

Step 4: Add Oppo_Custom.bin Manually (If Missing)

If your firmware doesn’t include Oppo_Custom.bin:

1. Extract from another working Realme 1 firmware.
2. Copy it into your firmware folder.
3. Re-load scatter file to refresh partitions.

Final Verification

After flashing:

• Reboot the phone manually if it doesn’t start automatically.
• Enter recovery mode to wipe cache/factory reset (optional).
• Ensure the device boots without display or logo glitches.

If it still fails, try the Fixed Firmware (Oppo_Custom patched) version available on MobiFirms.

Pro Tip

Always use official firmware and signed tools. Avoid random firmware shared on forums; they often miss critical partition files like Oppo_Custom.bin.
For easy access to verified firmware and flashing tools, bookmark MobiFirms.com — all files are 100% tested and safe for technicians.

Need More Help?

If your Realme 1 still shows flashing errors or boot issues, download the Realme 1 Fixed Firmware Package from MobiFirms. It includes patched files and guides for FRP unlock, bootloop repair, and IMEI restore.