Based on the current status and future plans, it is recommended that:
| Error Message | Likely Cause | Solution | |----------------|----------------|------------| | "JUF384 UPD signature mismatch" | Corrupted download or incorrect file for hardware revision. | Re-download the file; verify against vendor checksum. Do not force flash. | | "Flash erase failed at sector 0x..." | NAND flash has developed bad blocks. | Run nand scrub if available, then retry. If persists, replace hardware. | | "Bootloader locked" | Secure boot is enabled, and the update is unsigned. | Obtain a signed package from the OEM. | | "Timeout waiting for UPD packet" (serial method) | Baud rate mismatch or line noise. | Reduce baud rate to 57600 and enable hardware flow control (RTS/CTS). | | Device is completely unresponsive after reboot | Bootloader was overwritten incorrectly. | Use JTAG/SWD programmer to reflash bootloader from external debugger. | jufe384 upd
Do not interrupt the power supply during the update process. A brownout during the bootloader rewrite will necessitate a JTAG recovery. Based on the current status and future plans,