Lambda tensorbook stuck in lambda logo and doesn’t boot

Hi Lambda technical support, today my lambda tensorbook suddenly doesn’t boot any more, it always stuck in the very beginning showing the lambda logo. I tried press DELL key but can not enter boot bios setup menu, also tried CTRL + ALT+F3 and also tried F2, none of them works. Could you please tell me what could be wrong and how can I enter boot setup menu so I can boot from USB drive?
Thanks
Edward