Fix Oppo F1s Download Not Completed Error | Oppo_Custom.bin Solution

If you’re flashing Oppo F1s firmware and get the “Download not completed” error in SP Flash Tool or MSM Download Tool, you’re not alone. This issue commonly occurs due to the Oppo_Custom.bin file mismatch, missing partition, or corrupted firmware. In this guide, we’ll explain the exact cause and show you how to fix it step by step.

Why the “Download Not Completed” Error Appears

When flashing Oppo F1s (A1601), the flashing process may stop at Oppo_Custom.bin or fail midway. The error usually comes from:

• Wrong or mismatched firmware version (Region or build mismatch)
• Corrupted Oppo_Custom.bin file
• Missing preloader or secure boot mismatch
• Incomplete or damaged flash files

These issues can prevent the flash tool from completing the write process to NAND/eMMC storage.

Step-by-Step Solution for Oppo F1s Download Error

Step 1: Use Official and Tested Firmware

Always use a 100% tested firmware compatible with your Oppo F1s model (MT6750). Download the firmware directly from a trusted source like MobiFirms.com.

• File name example: Oppo_F1s_A1601_11_A.35_160917.zip
• Ensure it includes Oppo_Custom.bin file inside the firmware folder.

Step 2: Replace Oppo_Custom.bin File (If Corrupted)

If flashing fails at Oppo_Custom.bin, replace it with a working copy:

1. Extract another working Oppo F1s firmware.
2. Copy the Oppo_Custom.bin file.
3. Paste it into your current firmware folder (replace the existing one).
4. Reflash using SP Flash Tool or MSM Download Tool.

✅ Pro Tip: If the error persists, delete the Oppo_Custom.bin entry from the scatter file (for advanced users only). The device will boot without it in many cases, but keep this as a temporary workaround.

Step 3: Flash Using Correct Tool & DA File

Use SP Flash Tool v5.1628 or later with a verified MTK DA file (MTK_AllInOne_DA.bin).

• Load the scatter file.
• Select “Download Only” mode.
• Uncheck preloader (optional if device bootloader is locked).
• Click Download.

Wait until the green success tick appears.

Additional Fix Tips

• Make sure the USB cable and port are stable during the flash.
• Don’t interrupt the process or remove the battery mid-flash.
• Use MTK VCOM drivers properly installed.
• Avoid modified/custom ROMs that may contain broken partition maps.

Conclusion

The Oppo F1s Download not completed error mainly points to a corrupted or mismatched Oppo_Custom.bin file. Replacing it with a valid one or using a complete, official firmware package fixes 90% of cases. Always flash tested firmware from MobiFirms.com to ensure safe and successful recovery.

👉 Download 100% tested Oppo F1s firmware and tools from MobiFirms.com to unbrick, restore, or update your device safely.