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l008com Author

Level 1

92 points

Diagnosing MacBook Pro Hard Drive Cable Failure

I've been fixing Macs professionally (not through Apple) for well over a decade now. By far the most common thing I do is replace failing hard drives. While Apple's own tools (hardware test, Disk Utility) do almost nothing to positively confirm a failing hard drive, there are several other tools (SoftRaid, SMART Utility) that can read the SMART data and tell you for sure that a drive is failing. So unlike the Genius bar, I can quickly diagnose a bad hard drive without having to infer the problem through symptoms.

But one problem that I've noticed really being on the rise lately, is a failing hard drive cable in MacBook Pros. That's the little flat ribbon cable that connects the hard drive to the logic board. It also connects the sleep light. This is a much harder problem to diagnose, because it generally acts just like a system with a failing hard drive, but the drive will pass a real SMART test with flying colors. You might think "come on, how often does a simple cable really go bad?" Well, I've never had a traditional desktop style SATA cable go bad. But I've replaced a lot of these drive cables and I'm doing another one tomorrow. I never really know if it's going to fix the problem or not though...

... because, there's no way to directly confirm the cable is the problem. I know all about Apple service procedure. I know the official way to diagnose a problem is to start replacing parts until the computer is fixed, and that last part was your problem. But that's not how things go in the out-of-warranty world of independent Mac repair.

So I got to thinking. Computers with bad cables don't crash, or freeze. They just hang for a while randomly, then come back. JUST like a hard drive with lots of bad blocks. So what could be causing this? The only thing I can think of is SATA bus errors that only happen intermittently (on a scale relative to the amount of i/o calls a hard drive does). If that is the case, then there must be SOME kind of utility somewhere that can see these errors? There are plenty of utilities out that that have fancy 3D interfaces, but do absolutely nothing (tech tool etc). But there are a few tools that the Pros use that actually DO stuff. DiskWarrior and SMART Utility are the main tools. If I could find something that can somehow easily and definitively sniff out these bad SATA cables, that would make my life a whole lot easier.

Posted on Dec 20, 2016 4:44 AM

Top-ranking reply

wiseacre33

Level 1

14 points

Posted on Nov 3, 2017 10:44 PM

Thank you for your explanation of the 821-2049-A and 821-1480-A cable differences. I couldn't find that anywhere.

I just inherited a mid-2012 13" A1278 which previous owner said she hardly used in recent years because it got so slow. After resetting the system, wiping the drive and upping the memory from the original base 4gb to 12gb, I noticed a definite improvement. But still really slow and sort of hanging up when installing new OS and other large apps. Even now on MS Office 2016 and Final Draft I get a lot of beachballing. I'm thinking I should try swapping out the Hard Drive Cable and maybe put in a spare SSD I've got lying around while I'm there.

So the cable iFixit sells says it can replace both. But it's pretty costly at $44 (with bracket). I can find some others (with bracket) on Amazon for half of that. But those specifically say they are EITHER for the 821-1480-A cables OR the 821-2049-A cable. Not both. Should I just go with the newer version 821-2049-A?

You also mentioned that Apple modified the HDD mount so it would prevent the case from pressing on the HDD cable. Even tho you said it didn't eradicate the issue, is that something that I can easily accomplish by replacing both brackets?

Any advice would be greatly appreciated.

Thanks.

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62 replies

djk0402

Level 1

8 points

Dec 12, 2017 3:47 PM in response to l008com

Have a 2009 Apple Mac Pro with diagnosed bad hd cable. Certified Apple tech said because part is over five years old Apple won’t identify the part so he says he can’t replace it? How can the part be identified ... he said he’d replace it if he could identify and obtain the hd cable 13 in Mac Pro 2009. Any suggestions ?

Dec 12, 2017 7:19 PM in response to l008com

You were looking for a way to diagnose. Put a stripe of tape down, and if the problems is cured, replace the cable as a permanent fix (but maybe leave the tape). This could be much more satisfying than "replaced cable and came clean".

If Brue computing is correct, the mechanism is explained by abrasion, and answers why these Macs and not every device that uses similar flex cables.

There is a close up of an abraded cable in his Video as well.

Jan 13, 2018 6:44 AM in response to ludofrombangkok

If the flat wire was faulty again, it would fail on both the original HD and the SSD without discrimination, right ?

Not necessarily. The experience of users here is that the rotating drive can work fine, the SSD can fail miserably, and the fault can still be the cable.

Also, where did you put your felt? At the bend point as the Original Poster proposed, or along the inside of the case, as Brue Computing proposed? or both?

Jan 13, 2018 6:45 PM in response to Grant Bennet-Alder

Thank you so much Grant,

So I will try a fresh cable and see if the SSD works after that.

For now, the protection felt I put is only between the bottom of the housing and the cable.
I should actually try to completely insulate the next cable and put some at the bend too.

Again, appreciating your time and help Grant.

Jan 18, 2018 12:22 AM in response to Grant Bennet-Alder

Hello there,

I eventually decided to replace the ribbon.
After double check, I didn't protect the main "bend" (ribbon attached by the 2 screws going down the bottom of the housing) the first time I replaced the ribbon. So I did it properly with the fresh one. Also used tape on most of its surface.

Still, the 2 previous ribbons didn't have any specific mark of scratch or clear apparent damage...

Anyway, I re-installed the SSD back inside, did a little Time Machine trick and the machine is back super fast as balls.

Thanks every one once again for all the precious help and info.
Hopefully, this ribbon will last longer than the previous one.

Cheers.

Sergio-

Level 1

4 points

Jan 18, 2018 4:34 PM in response to l008com

At the beginning I couldn't believe that HDD cables were failing that often especially the Macbook Pro 13" A1278 2012 with cable model 821-1480-A which I have had to replace a few in the past year. Best way to diagnose this issue to me so far (after you see device passing all components tests fine and you still don't have a clue where the grief is coming from) is pulling out the hard drive and let it boot from an external usb adapter. If it boot just fine, consider replacing the hard drive cable.

y_p_w

Level 6

17,696 points

Jan 18, 2018 5:11 PM in response to Sergio-

Sergio- wrote:

At the beginning I couldn't believe that HDD cables were failing that often especially the Macbook Pro 13" A1278 2012 with cable model 821-1480-A which I have had to replace a few in the past year. Best way to diagnose this issue to me so far (after you see device passing all components tests fine and you still don't have a clue where the grief is coming from) is pulling out the hard drive and let it boot from an external usb adapter. If it boot just fine, consider replacing the hard drive cable.

I'm not normally one to criticize Apple for its basic designs, but this is one that seemed to be far more about form than function. This section of the Unibody MacBook Pro was not cramped for space (a 15mm drive could fit in there), and the average user never even sees the cable. A more robust (and less expensive) ribbon cable design could have saved a lot of aggravation. I do understand that it was mostly to get it down to that tiny little boxed shaped connector that goes on the main board, but if anyone could have made it work it would be Apple.

I'm wondering why some enterprising company hasn't produced an aftermarket replacement cable/connector, unless Apple has a patent on the connector to the logic board.

Jan 18, 2018 7:51 PM in response to y_p_w

That's right y_p_w,

Apple designs are usually spot on but when it comes to a super thin ribbon that has to be 90° bent nearly 5 times, rubbing on some not so smooth edges along the way and involved in such main function in a computer, it's basically designed to fail over (short) time.

Anyway, I guess (and hope) the more recent designs of MBP have capitalized on this failure.

Jan 18, 2018 7:55 PM in response to ludofrombangkok

I guess (and hope) the more recent designs of MBP have capitalized on this failure.

They have. That cable has been completely eliminated.

The solution chosen is to solder SSD components and Controller directly to the mainboard. No cables. No sockets.

y_p_w

Level 6

17,696 points

Jan 18, 2018 8:11 PM in response to ludofrombangkok

ludofrombangkok wrote:

That's right y_p_w,

Apple designs are usually spot on but when it comes to a super thin ribbon that has to be 90° bent nearly 5 times, rubbing on some not so smooth edges along the way and involved in such main function in a computer, it's basically designed to fail over (short) time.

Anyway, I guess (and hope) the more recent designs of MBP have capitalized on this failure.

Of course. Socket right on the main board or just solder the SSD and controller like on an iPad.

However, I appreciate the overengineering of this connector. It's a fabulous looking piece of equipment despite its obvious issues with fragility.

y_p_w

Level 6

17,696 points

Jan 18, 2018 10:44 PM in response to ludofrombangkok

ludofrombangkok wrote:

Oh yes silly me !!

All the following generations of MPB have widely upgraded to flash storages.

Have you seen how thin they are? Most of the space in the case goes to the battery now. The components for the SSD barely take up any space - maybe two BGA packages and the controller. The entire logic board (including CPU, RAM, and SSD) of the Retina MacBook can fit completely on my hand. The MBP is a bit bigger, but still an impressive feat of miniaturization of everything.

https://ifixit.org/blog/9185/2017-apple-laptop/

yytab999

Level 1

14 points

Jan 24, 2018 7:19 AM in response to y_p_w

After upgrading to MacOS High Sierra 10.13.2 a few weeks, my MBP 13 freeze and could not be booted (booting progress bar 100%, but no login page shows). I created a USB installer, and tried to clean install High Sierra. Clean installing can be done normally for the external SSD, and functions well. But installation could not be done internally for the same SSD. When the externally-installed drive was input as internal drive, it show dead pinwheel for any movement. In brief, the same SSD drive functions well externally, but does not function or act extremely slow as internal drive.

I reset SMC, NVRAM, but did not get any improvement. By the way, when swaping the externally-installed drive inside, I set the starting drive to it at the System Preference. I also checked the firmware version, and it seems the version is little behind for the MBP (13'; early 2011), but no newer version is available.

It seems the cable is culprit for the problem. Then, I replaced the drive cable (bought from Amazon) last weekend. But the situation did not improve. Is the new cable damaged during my installation (I was very careful in handling the cable)? Is it actually faulty cable? Or something else could cause the problem. I still suspect the drive cable, and re-ordered another one which is on the way.

Very frustrated. So far, none of the effects worked.

Any suggestion, or clue in solving the problem will be appreciated!

yytab999

Level 1

14 points

Jan 24, 2018 11:48 AM in response to yytab999

The problem in internal drive dysfunction (mentioned above; the same SSD drive externally works fine) seems to be caused by the drive cable. But, after inputting a SSD drive harboring Mac OS X (version 10.7.5) and my data, which is from a few years ago, the MBP now works normally with this old SSD! No more pinwheel. No any symptom for a possible dysfunctional drive cable (or other parts)!

I am completely lost. Why High Sierra can not be operated any more from internal drive, but can be functional well externally? If the drive cable caused the problem, why Mac OS X Lion does not raise that kind of issue? Hardware, or software problem?

Apple, or anyone, please help!

yytab999

Level 1

14 points

Jan 24, 2018 7:10 PM in response to Grant Bennet-Alder

Hardware Overview:

Model Name: MacBook Pro

Model Identifier: MacBookPro8,1

Processor Name: Intel Core i5

Processor Speed: 2.3 GHz

Number of Processors: 1

Total Number of Cores: 2

L2 Cache (per Core): 256 KB

L3 Cache: 3 MB

Memory: 8 GB

Boot ROM Version: MBP81.004D.B00

SMC Version (system): 1.68f99

Jan 25, 2018 6:20 AM in response to yytab999

that looks like it has the right firmware upgrade already, so that is not likely to be the problem. false alarm.

The first new cable could be the problem. Some users found their original cables supported their old drive (which transferred data more slowly) but failed with the newest, fastest SSD drives. so perhaps the increased speed of your new SSD drive is causing the failure to show up.

If you have a new cable coming, what happens with that newest cable will be interesting.

Diagnosing MacBook Pro Hard Drive Cable Failure