MacBook Pro making crackling sound on first open
When I first open my MacBook Pro (15" Retina Display Mid 2012) after it has been asleep for a while, it makes a crackling noise in the upper right area, near the power button. At first I thought it could be related to the hinges, because I have recently been having an issue with the lid not fully closing anymore. But, after this first open, when it has woken up, it doesn't make the noise anymore when I close and reopen the lid.
The lid has not been sitting closed for the last month or so. When I hold it down at the center, the left side seems to be sit normally, but the right side of the lid pops up 3/16" or so.
Could these two issues be related?
I was reading that a crackling noise at startup can indicate the hard drive is failing, but from what I've been able to find, the 15" Retina mid 2012 has an SSD and not a hard drive. Is that correct, or could this be a soon-to-be hard drive failure?
EDIT: just looked up how to tell hard drive vs SSD, and it does have an SSD for the physical drive. This reddit post/thread (with no clear answer) is a good description of it too: https://www.reddit.com/r/applehelp/comme...