MacBook Pro delayed booting + weird noise on pressing power button
This is the sound my mid 14' macbook pro makes when I press the power button (~4 seconds in): https://www.youtube.com/watch?v=lqg-hEUU...
It takes anywhere from 2 minutes - 10 minutes for the chime after pressing the power button. Sometimes even after 10+ minutes it doesn't chime, so I have to press it multiple times. I have tried resetting the SMC and the NVRAM multiple times, running disk utility which reported one issue (probably due to me installing a 3rd party SSD years after the issue first started happening). None of them helped.
This issue has persisted for at least 4 years. The machine otherwise works flawlessly. Current OS is Mojave and a clean install from not long ago. Now I understand there must be hardware damage (possibly due to liquid spillage). However, does anyone know what's the possible damage? I'm hoping to do some repairs myself if they are feasible.
Much thanks in advance!