Dell Latitude 7400 2-in-1 laptop no POST, stuck on Dell logo

Dell Latitude 7400 2-in-1

I have a no POST issue where the laptop wouldn't boot beyond the Dell logo. The LED flashing sequence (3 red, 6 white) points to a "SBIOS Flash Corruption" issue according to this Dell support page, which is consistent with the symptoms.

https://www.dell.com/support/kbdoc/en-us...

I followed Dell's instructions for performing BIOS recovery, but I didn't get the expected BIOS recovery screen:

https://www.dell.com/support/kbdoc/en-us...

I also tried performing forced ePSA and resetting the RTC clock as mentioned in the following pages with no observed change in behaviour:

https://www.dell.com/support/kbdoc/en-us...

https://www.dell.com/support/kbdoc/en-us...

I appreciate pointing me in the right direction to fix this.