Receiving Question Mark in Folder at Start Up

Texjauto wrote:

Unable to validate disk0s2 as it is unmounted. Select Mount and nothing happens

Thank you for the quick reply. Ran the diagnostic and came back with no trouble found (ADP000).

the base system is the Recovery volume.

the number scheme is relative not absolute...however I see disk0s2 as the  Apple_APFS ⁨Container(?)

From Internet Recovery can you make any progress w/ Disk Utility "Show all Devices"

Boot into Internet Recovery (Option Command R) and from the dropdown menu: Utilities>  Disk Utility> run the First Aid on your Macintosh HD (and the "Macintosh HD-Data" volume as well if Catalina/Big Sur/Monterey) If errors are found and repaired, run again until no errors reported.

Disk Utility>View>Show All Devices The best sequence is —

Volume level

Container level

Parent drive

How to repair a Mac disk with Disk Utility

How to repair a Mac disk with Disk Utility - Apple Support

ref:

https://apple.stackexchange.com/questions/305071/force-mounting-an-external-disk-that-is-not-recognized

Texjauto wrote:

macbook Pro/OS X (Retina, 13-inch, Early 2015)

At startup, receiving question marl within a folder.

Trying to resolve without losing user data but once all options are explored, can do fresh install.

Reset NVRAM (didn't resolve) then went into Disk Utility to Repair Disk

I am able to verify 251 GB APPLE SSD SM0256G Disk and the OS X Base System

Unable to validate disk0s2 as it is unmounted. Select Mount and nothing happens

Thank you in advance for any assistance.

Also tried to Reinstall OS but no disk appears when required to select disk to install.

If your Mac starts up to a question mark

If your Mac starts up to a question mark - Apple Support

Can you run the user Diagnostic...not as definitive as Apple's own AST2 (Apple Service Toolkit) back bench diagnostic, but may kick out an error code.

Use Apple Diagnostics to test your Mac

Use Apple Diagnostics to test your Mac - Apple Support