Level 1

101 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

IanD1953

Level 1

50 points

Posted on Oct 3, 2017 6:38 PM

I bought my MacBook Pro mid 2012 version back in August 2013 and I am just replaced the HDD cable for the third time.

I had kept the three old cables so I decided to find out what had gone wrong with them. There are 5 thin copper tacks, which connect to the 7 pin side of the SATA connector. I used a multimeter to do a continuity test on these tracks. I found that on all three cables one of these tracks had broken at the same place. The cable does a tight right angle bend at the point it passes over the optic drive. The cable flexes at this point and eventually one of the copper tracks breaks. I found that if I flexed the cable at this point the track would make and break contact.

On later versions of the MacBook Pro Apple modified the HDD mount so it would prevent the case from pressing on the HDD cable. They also introduced an upgraded cable 821-2049-A, which replaced the original 821-1480-A. Unfortunately, upgraded cable still eventually breaks. This time I have taped the cable to the optic drive to try and prevent it flexing. Time will tell if this helps. The cables are quite easy to replace and I keep a few in stock.

One way of partially checking the problem is to externally connect the HDD (e.g. use a dock or SATA to USB cable) and see if the MacBook boots correctly. You need to hold the alt key down when starting the MacBook to be able to select the external drive.

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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 4:01 PM in response to l008com

RE: SATA Cables:

Brue computing posted an interesting Video on Youtube. The proposition was that the SATA cable problems in certain MacBooks was caused by abrasion against the machined inside of the aluminum case. Their solution? RED TAPE!

(The drive has been removed for photographic clarity)

One strip applied to the case, and one strip applied to the underside of the cable.

You should use RED tape because it is associated with higher speeds, and will therefore keep the high speed bits from spilling out of the cable and accumulating inside the case.

OGELTHORPE insists that I have a fiduciary responsibility to tell you that--^

Many Users prefer to simply replace the cable than get involved with all this "red tape".

Jan 13, 2018 2:56 AM in response to l008com

Hello there,

Having some related trouble again... but a little confused to be honest.
So here's my timeline of problem:

- Mid 2016:

My MBP Mid 2012 shows a question mark in a gray folder (on white screen) when fired-up.
Thought it could be a HD failure. Invested in a brand new Samsung EVO 850 SSD and same problem occurred until I learned about the famous "Flat wire A1278" issue.
After replacement of the flat wire (with felt protection to prevent further damage) and entire recovery, everything was great, super fast booting, app opening in a blink of an eye, me happy.

(Note: I obviously kept the original HD just in case since there was actually nothing wrong with it at the first place).

End of 2017:
Same question mark in folder appears again when firing-up the machine.
Assuming the SSD was faulty, I swapped it against the original HD and Boom, the machine works fine again, well much slower but still.
Since it has a 5 year guaranty, I brought the SSD to a Samsung Service Center (Bangkok, Thailand) and 10 days after, they declared the SSD is actually fine and might just have needed a firmware update. Ok why not after all...
They printed out many screenshots of the Samsung diagnostic software showing that all was in the green and one last shot showing the SSD up and running in a Mac environment connected via USB port (attached pictures)...
"USB port connected" and "internally on a MPB connected" is something quite different... anyways...

Today,
I put the Samsung SSD back in and even if it appeared in the list of drives under Recovery mode, the SSD cannot be either verified, repaired, erased/formatted as it always ended up with the same error message (see attached picture).

So what could it be this time ?
If the flat wire was faulty again, it would fail on both the original HD and the SSD without discrimination, right ?

Would it be possible to have a SATA controller issue ? Still doing ok with the original HD but having issue only with the Samsung SSD ?

Would be delighted to have your thoughts on that.
Thanks in advance and Happy New Year.

Ludo

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 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

17,762 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

17,762 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

yytab999

Level 1

14 points

Jan 25, 2018 6:57 AM in response to Grant Bennet-Alder

Thank you Grant Bennet-Alder.

The current cable (newly installed last weekend) has a newer part number (821-1480-A) than the old one (821-1226-A). The old one worked well for High Sierra for a few weeks. I reordered a 821-1226-A cable which will be delivered soon.

By the way, I reversely format a SDD drive from APFS to HFS+ and clean installed MacOS Sierra (10.12.6). The result is the same - booting fine as external drive but not as in internal drive. Only the drive with MacOS X works.

valenja

Level 1

4 points

Jan 27, 2018 6:09 PM in response to l008com

Hey guys, first post on the forum :-D

Macbook Pro 13" Mid 2012, Serial # C02HP8YRDTY4

Since 2013 I've been going back and forth to Apple about this issue. HDD cable has been replaced now 7 times, most recently 2 weeks ago (Apple was awesome enough to issue a one time out-of-warranty repair). I was using my macbook pro as a desktop for 2 years, and finally decided this year decide wasn't fair. But long behold, the same repair was done, HDD cable was replaced. I know this repair will work for at least 2-3 months. I'm very grateful to this thread for shedding light on this design defect. Aside from this defect, I would not trade my macbook pro 2012 for any newer model. With Mac OS High Sierra my computer is still running smooth and quick.

I'm interested in learning if the "red tape fix" has this any long term effects?

JohnyFdz

Level 1

8 points

Mar 10, 2018 2:18 AM in response to l008com

I have a question, it's kind of weird and basically the same issue. I own a Macbook Pro '13 mid. 2012 A1278, I repleaced the SATA cable a few months ago (the original cable failed), and today I'm trying to install an SSD; everything works flawless when I start the computer with an external SATA adaptor to USB, but when I put the SSD in the internal SATA, it just doesn't work, but with the native HDD it does work. What do you guys recommend, should I change the SATA cable again? Same model (821-1780a), or an upgraded model (821-2049)?

JohnyFdz

Level 1

8 points

Mar 10, 2018 9:48 AM in response to IanD1953

I have tried also that, when I connect the HDD via internal, and the SSD via external, those bootable drives do appears, both of them, I can start the computer from any of the disks; but when I connect the SSD via internal, and the HDD via external, it only recognizes the external HDD, I can only start the computer from the external HDD (so annoying).

That's why I say it's a weird issue. Some people commented to me that it would be a compatibility failure, and that I should use a Hybrid Disk; but I have made sure that the SSD were compatible with my Macbook, both of them are supposed to be SATA III. The SSD is a Kingston Hyperx Savage 960gb, this is what they comment on the support page: "Our SATA III (6Gbit/s) SSDs are tested to be backwards compatible to SATA II (3Gbit/s). They are not designed or tested to be backwards compatible with SATA I ports (1.5Gbit/s). Most systems made before 2008 used SATA I ports. Our SSDs will likely not work in these systems."

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Diagnosing MacBook Pro Hard Drive Cable Failure