This phrase indicates that the Boot ROM is waiting to receive a boot file over a serial (UART) connection. It is actively listening for a signal from an external host (your PC) to upload a bootloader image.
The error occurs because the PC misses the 1-second window where the BootROM is listening. To fix this: This phrase indicates that the Boot ROM is
Most boxes have a reset button in the AV port. The standard "hold for 5 seconds" is wrong for this error. Most boxes have a reset button in the AV port
If the configuration is perfect but the error persists, the physical device may be damaged. Power-cycle device and observe any output
What to look for: