I’ve tried holding the power button for 10 seconds and then pressing power, and (while charger is attached) holding down shift+control+option+power for 10 seconds then pressing power. Now I’ve noticed that after fully shutting it off (charging cable disconnected and holding power for 10 seconds) when I press the power key once, there is a quick zip noise followed by a brief soft whir noise, and this combination of sounds repeats every 15 seconds. The screen remains black. After the noises repeated 5 times, I held down the power button to shut it off again and they stopped. Does that repeating noise sequence indicate what’s wrong and why it won’t turn on? Would appreciate any help, I don’t have any tools to open it up. Let me know if I should buy a screwdriver if I’m able to fix the issue myself. Thank you.