When we notice a flashing question mark at startup session of a Mac computer, it signifies two qualifying issues:
- First, drive is failing or macOS crashed.
- Second, SATA assembly is malfunctioning or the assembly connection is loose.
What precautions to apply while seeing a flashing question mark on an Apple computer?
It is always wise to check whether data is in priority. As long as the data is safe in a backup drive, there is less to worry about. Next attempt is to make sure whether the partition of the drive is healthy. Reformatting drive freshens up a new partition and makes it ready for a fresh new macOS installation. In case the drive has hardware failure, it may less likely allow repartition. If such is the case, replacement of the drive is a preferable resolution.
Drive related issue
Many folks out there try reinstalling macOS to resolve ongoing drive issues. This is a wrong approach. When computing environments advance and drive values decrease, replacing drive is a better choice. There was a time we knew very little about how directory structures web on a drive. We knew very little about how drives fail. Now technology has evolved but the drive structures have not changed as much. This is a mismatch situation; hence, any correction of the drive itself may result an adverse impact.
Therefore, I personally recommend to reformat drive each time it begins to show issues. Each time someone applies fix for a failing drive means as if suppressing a cancer to grow even nastier in near future. Do not apply a fix for a failing drive. If you suspect that it makes clicking noises, unpleasant noises or performs extremely slow, replace it with a good drive.
In case data is in the highest priority possible, and drive is significantly failing, reinstallation of macOS may become counter productive. Secure data first. If you do not know how to secure data, approach a data recovery shop on time.
SATA assembly related issue
On the other hand, SATA assembly related issue is safer to deal with. The replacement of the SATA cable may help function the Mac normally. In this case, data stays safe and drive is in good health. And this is also easy to figure out by starting up Mac in recovery mode. If the recovery mode section Disk Utility does not show internal drive, it is most likely that the SATA assembly is malfunctioning.
If the Disk Utility shows the drive but the drive letters are in red color, replace drive. Red denotation refers to a hardware failure. On such, the drive is not reusable. If data is involved, rush for data recovery as soon as possible.