Latitude 7400 2-1 in not booting up, failed to update BIOS.

Whenever I press or hold the power button, the light button at the front glows orange, in accordance with the button presses, if I press it for 5 seconds, it will glow for 5 seconds at the same time. If I press it a certain number of times, it will sometimes turn on, the power button glow, the keyboard light up too, but after 30 seconds, it'll just turn off again, only the Dell logo comes on screen then vanishes with the other light. I tried to press F12 to load the emergency menu numerous times but it turned off regardless. I've had this issue on and off for a while, but this is the worst it's been. Earlier on in the day, I used the assistant app to do a scan, and it detected an update I hadn't installed, a BIOS update from the 10th of June. I attempted to try and download it twice, both times it said it failed. What is this issue and are there any fixes? Currently can't even access the emergency menu. Many thanks.