Sometimes we meet problems that control board cannot become normal, and also device is not pingable. After login with console port, we find the board reboot continuously in BIOS mode. That means extended BIOS cannot lead program. In this condition, we need re-load extended BIOS in BIOS mode.
In a word, we need load extended BIOS in basic BIOS mode to restore this issue. Attached document can lead you to load the extended BIOS correctly.