Folder question mark off and on

Hello all,

I have an MBP 2012, retina display, with upgraded RAM, SSD, new battery. Yesterday, out of the blue I turned it on and the folder with a question mark comes up. The problem comes and goes, that is, sometimes it will turn on as expected and I manage to log in and work normally and other times it simply will not log on and the folder with a question mark keeps coming up even after restarting it a number of times.

I have tried to run a diagnostics ( pressing D key while turning on) and it only accuses that the battery needs to be replaced. but the battery seems to be healthy, probably not to apple’s standards, which is not surprising since it is a third-party battery (obviously given the age of the MBP).

I have tried the cmd+R command and using the Disk Utility and running the Verify Disk. The report comes back ok, with no issues with the SSD. However, when I try to run the Repair Disk I get back an error message “some information was unavailable during an internal lookup”. I don’t know what that is about.

I tried disconnecting the SSD and connecting it back on to see if there was anything wrong with the cable, but that didn’t help.

I also tried the NVRAM and PRAM, but to no avail.

My question is: Is my SSD dying and should I replace it, or should I try formatting the SSD and reinstall the OS back on.

Thanks in advance.