Not cheap, but effective.

My Problem

MBP booted up into flashing "question mark." My first thought ran to HD failure. I prayed it was not the motherboard.

My Fix

Thinking a new SSD would affect both an upgrade AND a successful repair, I tried this solution, but to no avail. I found a YouTube video where a guy says to check the ribbon cable that connects to the HD. I had already begrudgingly spent $$$ for a new SSD, and I was bristling at the thought of shelling out almost as much for the new cable. They are not cheap! But I popped that boy in there, ran the recovery, and downloaded OS X for a clean install. The rest is history, as they say.

My Advice

In my case I was fortunate to be able to do my own repair; it was as simple as using a screwdriver. I also used the opportunity to upgrade my machine by replacing old HD with a new SSD. So this was a win-win, definitely.