Hello M2ABRAMSTANK,   Thank you for the update. I want to confirm you did leave it set for 3 minutes before reconnecting and powering up again after the flea power drain? There should be a wait time for the DRAC to reset without any power.   What is the BIOS version you are on?     Try Clear NVRAM - there is a map under the lid to show the jumper location. Shut down,  Set jumper to the Clear position, power on and Post up to the jumper error, shut down and return to original location. Boot normal and check results.
I purchased a dell PowerEdge R720 secondhand recently, and noticed that its bios and iDRAC firmware were 5+ years out of date. Upon trying to update the iDRAC however, I ran into an issue attempting to upload firmware past version 2.10.10.10, as it would give me an error of "upload failed" whenever I tried to run it from the remote update function through the iDRAC web portal. Upon rolling back and attempting to just upload any firmware past v2.10.10.10, the update completed successfully, and the server booted as normal, however the iDRAC web portal was unusable, as I was able to sign in, however nothing would load. I then reset the firmware back to 1.66.65, and everything was working normally. In addition to this issue however, I also ran into an issue whenever attempting to upload firmware locally through the lifecycle controller, as it would state that there was an issue verifying the credibility(paraphrasing here as I am writing this later than I was working with the server)What solutions are there to problem #1? Much thanks for your help!
PowerEdge R720 unable to update iDRAC