Oppo A5s CPH1909 Firmware Download Not Completed Error Fix (Oppo_Custom.bin)

If you’re flashing your Oppo A5s CPH1909 and facing the “Download Not Completed” error in SP Flash Tool or MSM Download Tool, don’t panic — this is a common firmware flashing issue caused by a missing or corrupted Oppo_Custom.bin file. In this guide, we’ll explain the reason behind this error and how to fix it safely using the correct Oppo A5s firmware and tools.

What Causes the “Download Not Completed” Error?

This error usually appears during flashing or firmware upgrade when:

• The Oppo_Custom.bin file is missing or mismatched.
• The firmware version doesn’t match your device’s region or build number.
• The preloader or DA (Download Agent) file is incompatible.
• You are using an outdated MSM Download Tool or SP Flash Tool version.

In short, it’s a firmware compatibility issue, not a hardware problem.

Tools & Files You’ll Need

Before starting the fix, make sure you have:

• Oppo A5s CPH1909 official firmware (100% tested)
• Oppo_Custom.bin file (matching your firmware build)
• SP Flash Tool or MSM Download Tool (latest version)
• MTK USB drivers installed on your PC
• USB data cable (preferably original)

You can download the official Oppo firmware and the fixed Oppo_Custom.bin file directly from MobiFirms.com.

Step-by-Step Fix Guide

Step 1: Extract Firmware

Unzip the downloaded firmware package and ensure that Oppo_Custom.bin exists inside the “Firmware” folder. If it’s missing or corrupted, replace it with the tested file from MobiFirms.

Step 2: Install Drivers

Install MTK USB Drivers. On Windows 10/11, disable driver signature enforcement before installation.

Step 3: Load Firmware into SP Flash Tool

• Open SP Flash Tool.
• Load the scatter.txt file from your firmware folder.
• Make sure all partitions are checked, especially Oppo_Custom.bin.

Step 4: Flash the Device

• Power off your Oppo A5s.
• Connect it to your PC using the USB cable.
• Click Download in SP Flash Tool.
• Wait until the process completes successfully (green tick ✅).

If you’re using MSM Download Tool, make sure you run it as administrator and use the proper auth file if required.

Step 5: Reboot and Verify

Once flashing is complete, disconnect the phone and power it on. The device should boot normally without the “Download Not Completed” message.

Pro Tips

• Always match the firmware build number to your phone’s current version.
• If flashing still fails, try Format + Download mode in SP Flash Tool.
• Backup your NVRAM and IMEI before flashing to prevent network issues.
• Keep a copy of the fixed Oppo_Custom.bin file for future repairs.

Conclusion

By following the steps above, you can easily fix the “Download Not Completed” error on your Oppo A5s CPH1909. This solution ensures a safe and successful flash using the correct Oppo_Custom.bin and official firmware.

👉 Download tested Oppo firmware and fix files now on MobiFirms.com to restore your device without risk.