It could still be a harddrive issue. My boyfriend's ProBook (Late 2011 model) had the exact same thing happen just this week. You can try to boot your Mac from an external drive to see if it will bypass the harddrive to try and rule out the HD.
If your Mac is older than 2013 (You didn't specify), you can shut the computer down, press the D key, and while holding it turn the computer on. It'll take it a bit to start up. After the language prompt, you can choose which test you want to perform. It will tell you if your HD is OK or not.
Another thing you can do is try Mac Recovery from the site.
Now, if it's not the HD, and Mac Recovery doesn't work then it's more than likely the Logic Board.