Notebook Operating System and Recovery

Hi all, my Spectre x360 will not start up. I left it plugged in on my desk over the weekend and it would not start up again on Monday. I had previously had some issues with it getting stuck in sleep mode when plugged in and needing to be power cycled to get it awake again. This time, power cycling has no effect.

Symptoms:

-When I press the power button to start up, it illuminates like it’s going to start. There is no sound, beeps, or fan movement, and the power button begins to blink 3 sec on and 3 sec off like it’s in sleep mode

-Holding the power button for 30 sec will turn off the laptop, and it charges normally when powered off

-When the AC adapter is plugged in, if I push the power button, and the power button flashes on and off in 3 sec intervals, the charging port LED blinks off when the power button blinks off, and the charging port LED then immediately comes back on and stays illuminated as the power button blinks on

Solutions I’ve tried:

- Holding the power button for at least 15 seconds, 30 seconds, or 45 seconds to power cycle the laptop. Computer will not start up after power cycle 

-I removed the battery and held the power button to drain any remaining battery power, then plugged in the AC adapter and tried to start up. Computer did not start, no change in symptoms

- Used theWindows key + V + power button combo to access BIOS. Computer did not start even holding the windows and V keys for 45+ seconds after releasing the power button

- Used the Windows key + B + power button combo to access BIOS. Computer did not start even holding the windows and B keys for 45+ seconds after releasing the power button

- I checked for any obvious scorching or burns inside the laptop. All components appear normal

- I replaced the battery with a new one. The computer did not start up with battery power, and did not start up with the new battery installed and the AC adapter plugged in

- I created downloaded the appropriate BIOS driver from the HP website and followed the instructions for updating BIOS with a USB drive (https://support.hp.com/us-en/document/ish_4129273-2331498-16). I cannot get the UEFI menu to appear using the esc key after pressing the power button. The power button briefly illuminates, and then flashes in 3 sec intervals as before, and the computer does not start.

Would appreciate any thoughts or additional steps I can take to get this resolved!