Possible "Software" issue on startup with flashing folder

Next step would be to replace the hard drive.

The folder means it cannot find the startup drive.

Reset NVRAM, How to Reset NVRAM on your Mac - Apple Support

then ensure the correct disk is set in the the Startup Disk System preferences.

Startup – Question Mark

Startup – Red Screen

Startup Issues - Resolve

Startup Issues - Resolve (2)

Startup Issues - Resolve (3)

Hello. Sorry to hear you're having problems, but i've encountered this issue many times. Your HDD is failing. It's pretty rare to experience a bad HDD cable in a MBP (they are packed in there tight... it's pretty unlikely to move much, if at all). If you haven't already, back up your data. Your next step should be to figure out if your drive is still under warranty and if so, repair/replace it.

You can test this out by purchasing another HDD that is known to be good, install it and your OS. If the computer boots up, then you know. If you're still having the issue, then I'd point to the logic board's HDD controller failing. At that point, you should go to Apple for a depot repair.

The age of the drive doesn't matter too much. It happens from time to time, and is generally pretty random. Good luck.

It is not so rare to have a bad cable, especially on 2010 and 11 MBP's. I would consider replacing the cable.

I still would rule out the cable unless something really torqued it. It's not out of the realm of possibility, though this issue is very remenicent of two things I've seen commonly in my days as a consultant, and now managing the desktops for a reasonable sized office (+100 macs). Without actually troubleshooting it myself, it really sounds like a bad/failing HDD. I'd try it with a known good HDD. If you don't have backups, then I wouldn't wipe the old drive. Putting it in and using it to boot off of, and getting consistent boots (5/5) should suffice enough to say "yeah, it's the drive," and pack it up for repair.

If you _still_ get inconsistent booting with the former drive, then I would point at the logic board. I've recently had an iMac that had a failing HDD in it. Replaced the drive, and two months later started seeing the same issues. The controller in it is bad and killing HDDs, though over a longer period of time.

All of that said, this comes from the standpoint of having already replaced the cable (which you've done), and if you're strapped for cash, couldn't hurt to try again. The inconsistent nature of your issue, and the fact that it's getting worse though, in my opinion, is that you're suffering hardware failure that is only seeming to get worse.

Good luck. We're all counting on you.

Rick46580 wrote:

I still would rule out the cable unless something really torqued it.

I will disagree, a short search of this forum will show that it is in fact relatively common, especially on 2009 through 2011 machines. The cable lives sandwiched between the chassis and the HDD, a device that vibrates at a high frequency, it gets heated and cooled and goes through 3 right angle turns. It also was designed at a time when 70MB/s was a high transfer rate, SSD's can achieve 550MB/s.

Changing it is quick, simple and cheap, it should be standard procedure when changing a drive, especially for a much faster drive.

Replace the cable and this SSD will work in the OP's Mac. I'll place money on that.

I'll take a drink, over the money. 😉 The original poster mentioned they had already changed out the cable, hence my next suggestion. Personally I've not experienced a bad cable, though maybe that's just me.

Cheers!