[Help] F2-423 Failed TOS 5→6→7 Upgrade: UEFI Shell Stuck, Bootloader Partition Lost & Clean NVMe/SSD Install [SOLVED]

[321PeteD]

Model: TerraMaster F2-423 (Intel Celeron N5105)

Target Goal: Perform a clean TOS installation on a new SSD (and ultimately migrate the OS boot drive to NVMe), then safely remount the original RAID 1 array, or recover the data from the RAID 1 array, and use a single disk.

Background & Sequence of Failure:

Failed Upgrade Sequence: The issue originated while attempting an OS upgrade path from TOS 5 → TOS 6 → TOS 7.

Web Access Loss: Mid-upgrade, the web UI became inaccessible.

SSH Recovery Failure: Attempted to log in via SSH to repair/update the installation manually. The OS crashed further during this process, dropping network access entirely.

Current Diagnostic Setup: Connected an HDMI monitor and USB keyboard directly to the NAS. The unit now either loops/beeps every 30 seconds or drops directly into the UEFI Interactive Shell (Shell>). LAN port LEDs remain dead.

Hardware Isolation Steps Performed:

Motherboard Health: Verified hardware health by booting a spare Windows SSD via HDMI. The NAS POSTs and boots Windows perfectly, proving the CPU, RAM, and board controllers are functional.

Data Preservation: Pulled the original two 12TB HDDs (configured in RAID 1 with all personal data backed up) to keep them safe from accidental formatting. Removed 2 NVMes.

USB Flash Attempts: Attempted to re-flash the internal 240MB USB boot drive using official recovery image (common_bootloader_V5.1.48.img).

Flashing Tools Used: Rufus, balenaEtcher, both gave me errors, but I ignored them. Also used Win32 Disk Imager.

Errors Encountered: balenaEtcher throws a "Missing partition table" error. Inspecting/extracting the image payload reveals Linux root system folders (/www, /etc, /sbin, /usr) rather than an executable EFI/BOOT/bootx64.efi partition structure.

UEFI Shell Mapping: Running map -r in the UEFI shell only lists block devices (blk0, blk1), with no filesystem mappings (fs0:, fs1:) available, preventing execution of startup.nsh or .efi files.

Questions for TerraMaster Support / Community:

Can you provide a link to a full, pre-partitioned raw USB disk image (containing a valid MBR/FAT32 EFI boot partition) for the F2-423 rather than the raw OS rootfs payload?

What is the recommended procedure to execute a fresh TOS 5 or TOS 6 install on a new SATA SSD (or NVMe drive) using the clean bootloader once network access is restored?

What is the proper sequence to safely re-insert and remount the original 12TB RAID 1 storage pool without the installer forcing an array re-initialization/format?

[crisisacting]

You might need to do the following to resolve the boot issue: https://forum.terramaster.cn/viewtopic.php?t=5211

The initboot for TOS 6 UEFI for your TNAS series is available @ viewtopic.php?t=6433 (there hasn't been a TOS 7 revision added to that thread, however maybe a TerraMaster employee which reads this, can update that thread with one or provide it to you privately if it's still not in release status).

[321PeteD]

I found this page with links to the USB Initboot. Hopefully it fixes it. I don't know why these files weren't linked from the downloads page for the F2-423.

https://help.terra-master.com/faq/TNAS/ ... b-initboot