Device Unresponsive After Firmware Upgrade to v7.2.9

Device Unresponsive After Firmware Upgrade to v7.2.9

The FortiGate 400E has become completely unresponsive. The unit exhibits the following behavior:

• Power LED: Solid green

• Status LED: Flashing rapidly (continuously)

• Console Access (PuTTY or Tera): No output observed during boot-up

• USB Recovery: No response when using a properly formatted USB drive with valid firmware image

• TFTP Recovery: No firmware request or activity detected from the device; unable to initiate recovery due to lack of console access

Multiple recovery attempts—including use of different cables, terminal software, USB drives, and TFTP configurations—the unit does not respond or enter bootloader mode.

seems bootloader failure triggered during the upgrade process.