How downgrade brand new empty N5810 from OS7 to OS5 via USB

Please try following steps to re-flash the USB DOM back to N5810:

1. Please download the attached USB tool "OS7_Upgrade_FW_v0.1.zip" or

2. Please unzip the downloaded file. There should be a folder called "OS7_Upgrade_FW_v0.1.zip".

There would be sub-folder "gofactory".

3. Please download firmware and MD5 file for firmware from the links below:

Firmware & MD5 file:

4. Please prepare an empty USB drive and format the USB drive as FAT32.

5. Please copy all the content under folder "OS7_Upgrade_FW_v0.1.zip", the firmware file and the MD5 file to the USB drive.

The content of USB drive should be like the attached screenshot.

6. Power off NAS

7. Plug USB drive into NAS black USB2.0 port as possible.

8. Power on NAS

9. It will start re-flashing DOM process automatically.

10. Once the process is done, NAS will be powered off automatically.

11. Remove USB drive from NAS