Diagnosing MacBook Pro Hard Drive Cable Failure

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.

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".

Hi,

Do you ever notice any physical wear on the cable? One youtube "fix" I saw involved simply insulating the cable with a piece of tape from the MBP's case where it had actually scraped a tiny portion of the very thin insulation off.

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.

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

IanD1953 wrote:

I had a close look at my stock of MacBook SATA cables before suggesting the problem could be a tolerance error. It only takes one of the contacts in the cable’s connector to be jamming slightly. In which case a tolerance difference for example between the HDD and SSD PCB thickness could make the difference between on drive working and the other not.

It was pretty clear to me that your claim about a damaged connector was about the "cable" (SATA female receptacle) side and not the drive side. The drive side has the "flat wiping contacts" that Grant was discussing. The connector side has a receptacle with bent spring contacts that can be damaged with improper force. Here's a picture of a SATA receptacle. Obviously it's not the specific MacBook Pro SATA connector, which is custom made for Apple, but Apple's connector has bent spring contacts (that can be damaged) like pretty much every other SATA receptacle.

Thanks for that. Out of interest I took a photo of the connector on a new Apple cable. There is not much difference. The interesting thing is that connector contacts on a broken cables I bought on ebay doesn't appear to be gold plated. That cable only lasted 2 months so I wonder if it was genuine Apple cable.

RMFT76 wrote:

I got the impression that Apple had accepted there was something of a design fault with this cable and that at one time they had a policy of replacing it for free and although that policy had expired, as a gesture of good will, they were prepared to honour it in my case.

That sounds like they did the right thing. However, I'm wondering how it might affect those with older MBPs that Apple considers "vintage". The part is basically the same.

The whole set of laws/regulation under the EU/UK seem more or less toothless. Doesn't the statutory 5 to 6 year warranty in the UK say that the defect had to be present at delivery? So something just wearing out after the warranty is over doesn't apply. Also, the responsibility is on the seller past the manufacturer's limited warranty. If it wasn't purchased directly from Apple, they could disavow any responsibility if they chose.

Apple Products and Consumer Laws in the United Kingdom

Any defect or non-conformity of goods with the contract which becomes apparent within 6 months of delivery are presumed to have existed at the time of delivery. After the expiry of this 6 month period, the burden to prove that the defect or non-conformity of goods with the contract existed on delivery generally shifts to the consumer.

Hi I am facing this problem too. I have a '11 macbook pro 13" and replaced HDD at first (having two of them I did it effortless and moneyless), then without any fix decided to buy another HDD cable and problem seemed to be fixed. I faced the same issue again, still after the same amount of time (avg 3 weeks) so the flat cable failed again. I am currently at the second cable bought and decided to not go for any buy again by now.

At the first fail the cable appeared intact, last time, instead, I felt a smell of hot plastic and observed a polished round area on the tracks leading to the HDD, clue that cable was gone again.

I have no clue about the reason of the failure.

Hi,

I'm having the same issue in my wife's MBP, we attend to the Apple Authorized Service Provider, this has been replaced two times, they mention that a batch of HDD flex had this issue and that they will replace it until the issue goes away, but in the meantime now due some random restarts that sometimes happen,

The Hard disk starts to make some noise (this in a period of ~1 year ) is there an official apple recall or a communication from apple side regarding this issue?

Or how can we communicate this to apple and that they take the responsibility of their product, since we bought it the MBP never has been working as should, we have another MBP same year, same day of purchased and works totally different, or better to say: works! is responsive, turn on and off fast, etc.

What do you think we can do in this situation?

Thanks in advance!

Ernesto

Hello, I have the same problem, my data cable, but I have a question if someone can help me, the part is 821-2049-a in my macbook pro, and I get the cable but the model in this new is 821-0814-a. Is there some difference ? Because my MBP Mid 2012 is working, but sometimes get freeze when I click something or trying to refresh some websites, or opening some programs. Thank you so much!!!

l008com wrote:

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?

Internal cables are actually not cables but flexible circuit boards, usually mylar, with printed circuit traces taking the place of wires. This type of cable can experience cracks in traces due to aging, heat, vibration, impact and abrasion. They can be damaged quite easily if the unit is mishandled during assembly or re-assembly.

In the case of an intermittent generic failure, the electrical continuity of a cracked trace on both sides of the crack is very often a function of the temperature of the unit at the point where the crack exists. As a unit heats up, it expands, and as it expands, the crack widens, eventually forcing a complete electrical separation to exist on both sides of the crack, hence a failure. As it cools down, electrical contact may once again be restored.

Addendum—I see now this thread is almost a year old. If the HDD/SSD is removable it has always been the go to way to diagnose by putting it in an external enclosure bypassing the internal SATA cable. Nothing new here.

@leroydouglas Thanks you for the interesting comment on the thermal effects on the HDD cables.

I came across this old thread when I was looking to see if anyone had found a way of improving the life of the these cable. Given that the thread comes up high in a Google search and that it has had some quite recent traffic I thought it may be help to someone if I added my experience to it.

I agree that the use of an enclose to test the HDD is old news and the only reason for mentioning it was 1008com that had recently added a comment to the thread suggesting there was no definitive way to diagnose a problem with HDD cables. My view is that if the HDD works in the enclosure but not in the MacBook it makes trying a new cable worthwhile.

Woah! even I am having the same issue. I replaced the cable once, but again the replaced cable too failed. I took it to the Apple store genius bar, and they told me that either the cable has failed, or the logic board. But I can boot by connecting my HDD externally via USB drive. So guess it's the cable again. I have ordered a new cable and will hopefully fix the issue!

I was worried about the failing HDD or the logic board. But the symptoms you have mentioned exactly match mine.

I am helping a friend. She has cancer and doing work for free. She has a 2010 Macbook Pro and the original hard drive failed every test, including putting it a 2nd Macbook pro where I removed the DVD bay in place for a Sata hard drive bay. It failed there too. I purchased a 240GB Samsung SSD, same form factor as original drive. The disk utility (she saved OSX install disk) showed the drive, Smart Status=Ok, everything else looked fine, but when I tried to format said drive I came up with error "POSIX reports the operation couldn't be completed. Cannot allocate memory" Is possible that the SATA cable is bad and it is the root of the error?