Background: My macbook pro start to become unpredictable in beginning, sometime really slow, unusable slow and sometimes it starts work normally. I tried first aid from SSD but nothing wrong. After few days I started to get folder sign with question mark, not always. After couple days more, I got prohibited sign, but prohibited sign is not consistent on screen, after 8-9 seconds I see apple logo for second again prohibited sign for 8-9. And repeat. Can it be something related to cable connecting SSD or SSD itself. While trying to reinstall OS X, installed couldn't find any drive either.
It's possible, though unlikely, that the SSD itself may be failing. The SATA connector is a much more likely source of failure, and commonly occurs in those Unibody models. Replacements can be found on eBay cheaply, though make sure you get the right part for your model, as they vary in length.
You can also get a USB to SATA cable cheaply, so you can test the drive as an external, to see if it works there.