Bootloop and Power Button Failure on my Inspiron 7386 2-in-1 PC

I am having issues with my Dell Inspiron 7386 2-in-1 laptop. Whenever I unplug the power adapter when switched off, the PC powers on automatically. Whenever I shut down while the power cord is unplugged from the PC, it keeps powering back up by itself, and stays on till the power in the battery drains off completely. Whenever I plug in the AC adapter, and shut down, it doesn't reboot or power back up by itself. The screen went blank at some point (didn't display anything again), even though the fan was running and the keyboard lights came on. The power button seems not to be working anymore, as I can't use it to force a power down by long pressing it, neither can I use it to power it on again when I successfully shut it down while plugged into the power source.

I allowed the battery drain, then left it for some hours before plugging in the power adaptor. I pressed the power button after some minutes of charging but the PC didn't respond. I allowed it to charge for a bit longer, then unplugged the power adaptor. Alas, without pressing the power button, it powered on by itself after a few seconds. My screen also started to display again thankfully, and I have had to quickly do a backup before anything goes wrong with the screen again. I know my battery is still in good condition because it doesn't suddenly go off whenever I unplug the power adaptor while the laptop is running.

 My warranty coverage of 1 year with Dell is expired as well. What suggestions can I possibly try to solve this problem?