Chosen Solution
Updated with screenshots from Cocobattery as suggested by Dan and also snapshot of the diagnostic tool result Hello, My name is Allan. I have this Macbook Early 2015 that started acting weird. Recently, I upgraded it to Catalina and suddenly the SSD would disappear in the middle of the work and reappear a few minutes after I turn it off. A friend suggested that it could be Catalina problem because it was working fine on Mojave. I reformatted the disc and reinstalled Mojave but the problem remained whenever the laptop stays on for several minutes and heats up. Another friend said it could be a case of bad SSD so I bought a new one, installed Sierra and upgraded until Mojave. Still, the same problem occurs each time it heats up. Another friend said I should tighten well the SSD mounting screw. i did that too and the problem would not go away. The folder with a question mark would regularly appear. Any idea? Would appreciate helpful answers. Thank you.
Your battery still has quite a bit of life left! So you don’t need to worry about it at this point. The MagSafe power adapter doesn’t seem to be attached as the ‘Power Adaper’ tells us that. Do make sure when you plug it in you see it connecting, give it a minute to recognize the change. At this point I think you need to look at the SSD connector. Looking at the sides do you see any differences in the connector case?
You may also want to clean the SSD contacts using a fresh pink pencil eraser (still soft) go with the direction of the pins and then wipe the surface with 85% or better isopropyl alcohol using a cotton swab.
