Tuesday, January 7, 2014

Repairing intermittent wifi/wireless on a 15" Macbook Pro 2011

From reading a couple of articles on this site, you may have noticed that although I may be critical of some Apple goods, in general, I am a fan. However, there are some times that I am extremely fustrated when their hardware breaks, such as when my MacBook Pro 15" wifi decided to start acting abnormally. For reference, it have a Macbook Pro 15" Unibody Early 2011 (Released February 2011 2.2 GHz Quad-core Intel Core i7 Processor, thunderbolt, Broadcom BCM94331PCIEBT4AX wifi/bluetooth card)

The issue
After a while of use, the wireless internet dies. The signal strength indicator fan in the top right corner still indicates five full bars. Right Clicking on the icon and clicking on "Turn wi-fi off" makes the fan icon go blank as it should, but the previously connected to network remains in the list check marked, which it shouldnt. All other wifi networks in the area disappear from the list. The status at the top of the drop down box says "Wi-Fi: looking for networks".
Right clicking on the icon and clicking on "Turn wifi-off" makes the icon go blank, as it should. Right-clicking on the icon and clicking on "Turn Wifi-On" does not enable the wifi. The fan icon stays blank, which it shouldn't. The previously "connected to" network remains check marked, but there is no connection to the internet.
Putting the laptop to sleep with the lid and waking it again results in five faded bars, but now no wifi networks can be found, and there is no connection to the internet. The issue occurred round once a day at the beginning. By saving my work and rebooting the laptop, the issue has been manageable. However, it became unmanageable when it occurred more and more often to the point where I had to save my work reboot my laptop every 1-2 hours of use.

What I tried to do to repair the issue

  1. Reboot the laptop. A temporary solution is to reboot the laptop, in which the wifi performs as it should until the issue occurs again.
  2. Use a USB dongle. A semi permanent solution was for me to buy a Ralink usb wifi adapter, that worked fine but was not ideal. It felt a bit ridiculous and cumbersome to have to use a $10 usb adapter to repair a Macbook Pro that cost $2000.
  3. Connect to a different wifi network. This did not work. The issue occurs when connected to other wifi networks, such as my parents one at home. This hinted that it was not a wireless router issue.
  4. Reset PRAM, NRAM, etc. This was only a temporary solution, as was just simply rebooting the laptop.
  5. Deleting my Airport settings files. Again, this was only a temporary solution, bus so was simply rebooting.
  6. Wiped the harddrive and installed Mountain Lion. The issue remained, even with a clean installation with no restoration of my old settings from TimeMachine. The issue was the same when I installed Lion, and Mavericks. I even noticed the same issue once with the wifi when I booted off just the OSX installation disk. As such, I believed that the the issue is hardware related.
  7. Visual inspection of the hardware. I took off the bottom cover of the laptop to see if there are any visually obvious loose connections, but there are none.
  8. Took the laptop to an authorised Apple Repair Center. They did nothing. As it was an intermittent issue, they said that the wifi was working fine when they ran their DVD of hardware tests. As far as I know, they don't do any long-term tests, even though I had requested them to do so. They blamed the wireless router (which I knew was not an issue, see above) and mu wifi settings (which I also knew was not an issue, see above).
  9. Replaced the wifi card. This did not work. I bought a new Broadcom BCM94331PCIEBT4AX for around $35 off eBay. Following a guide on ifixit, http://www.ifixit.com/Guide/MacBook+Pro+15-Inch+Unibody+Early+2011+AirPort-Bluet ooth+Cable+Replacement/5887 I replaced the card easily enough. It was just around 10 screws in total, easily manageable in an hour if you take your time. Unfortunately, the issue returned again after a few hours of use. 
  10. Replaced the motherboard, and the screen. I assume means that the wifi antennas got replaced. This did not work. On an unrelated issue with the graphics card, Apple agreed to replace the motherboard, LVDS, and LCD screen out of warranty (really good of them). Unfortunately, their authorised repair center took nearly 6 months to do the repair (again, they were a bad representation of Apple). Unfortunately, the wifi issue returned once again after a few hours of work.

What repaired it in the end
Finally, in a last ditch attempt, and as it seemed to be the only part in the laptop not replaced (including software), I bought a replacement wifi/bluetooth cable off ebay for around $30. This worked! It has been going strong now for nearly three weeks with no drop in wifi. It was pretty expensive for a simple black ribbon cable but I am glad that it worked. There was no visual damage to the old cable, but I suspect myself that the bottom cover may have pinched the cable against some edge near the motherboard, thus causing the intermittent drop-off in wifi.

Update 20/01/2013 : I have re-opened the laptop to inspect the location of the ribbon cable (Figure 1). In (Figure 2) you can see the point on the rear of bottom cover (2) that places pressure on the end of the ribbon cable. You can see that there is a visible imprint on the plastic foil covering the back of where they are in contact. Due to the level of imprint and its location, I suspect that this causes excess pressure on the cable connector when the laptop receives knocks from the underside.

Figure 1: The faulty macbook wifi cable is shown in (1). The point on the back cover that I suspect may have been putting too much pressure on the ribbon cable is located at (2)

Figure 2: The point on the rear of bottom cover (2) that places pressure on the end of the ribbon cable. You can see that there is a visible imprint on the plastic foil covering the back of where they are in contact. Due to the level of imprint and its location, I suspect that this causes excess pressure on the cable connector when the laptop receives knocks from the underside. 


  1. Do you have a serial number or something for the cable? I found one online, but that's for the 13 inch - which might be different? And is it complicated to install, or can anyone do it? I'd love to get rid of the stupid USB dongle sticking out of my 3,000 euro Macbook Pro!

    1. Hi Jerry, The serial number for my 15" 2011 macbook pro was 821-1311-02. If yours is a 13", it may be different.

  2. We had the same problem at the office with one MacBook 15". WiFi would work after boot, but no longer when the Mac woke up from sleep. Eventually it lost the WiFi card altogether ("WiFi: no hardware installed" when clicking the menubar symbol). We tried to replace the WiFi card, but that obviously didn't help, as the cable was faulty.

    1. And now, changing the cable you solve this problem?
      i have the same issue on my macbook pro early 2011.

  3. Hi,

    I wanted to thank you for this article. I had similar problems on a MacBook Pro 13" Early 2011, where it started with WiFi switched off after sleep. They replaced the WiFi card on warranty, but the issue returned.

    Finally, I opted to order myself a cable to replace it, which worked flawlessly. So thank you for the hint. (Now on some networks I'm just stuck with full WiFi connection, but the alert that no internet connection is available. Despite the fact that it actually works.)

    @Jerry: my original (broken) cable had a serial 821-1312-A (MacBook Pro 13" Early 2011,)

    Cheers, Fabian

    1. Great news! I am glad that the solution worked for you as I could not find a similar one online.

    2. @Fabian thanks a lot for the serial number of cable.

  4. Man, I'm having this same problem with my MacBook Pro (late 2012, bought it brand new, two months ago). I've tried several different approaches, nothing works as a long term fix. I'm also seeing lots of people facing this issue too with many different models -- Air, Pro, Retina, etc. I'm still not sure why replacing the cable could fix the problem, but I will surely look for one in Brazil. :)

  5. Thank you - been having exact same problems on my 2011 MacBook Pro 15" and been searching for solutions - just ordered a new cable - your efforts are greatly appreciated

  6. I had the same problems... searching for the solution, I found your website.
    I just wanna say... thank you!! I bought a second hand flex (a bit longer that the original one, no silver plate on the top, I guess that it is from a different model) and now, my macbook pro i7 late 2011 works flawlessly!!

  7. I had the same problem on 2011 Macbook Pro 15". New flex cable installed. Works like a charm.

    Brilliant! Thanks.

  8. Great facts. Many thanks with regard to offering all of us such a beneficial facts. Maintain the great do the job as well as continue offering all of us far more quality facts every now and then. If at all possible, when you obtain ability, do you thoughts modernizing your blog along with additional information
    Wireless Internet Card

  9. Great post! I was lucky as all I had to do was reseat the cable and wi-fi came up as soon as I booted it. Thanks!

  10. I've solved! thanks a lot (only 10€)

  11. thanks for posting this!

    I had the exact same symptoms but thought the problem was the wifi card. after replacing the card twice, I gave up until i found this post. the weirdest part was bluetooth worked fine when i tethered!!

  12. Have almost the same setup as you but my computer is a mid 2010 15" MacBook Pro. The local Apple guys tell me all of the time that I need a new computer. Found this on eBay:

    15" 2010 Macbook Pro WiFi & Bluetooth Board w/ Bracket & Cable P/N 607-7147-A.

    Maybe I will try to re-seat the cable as well. Hope this works. Thank you for your service to all of us who hate to be at the mercy of Apple.

  13. I have the same issue with a Macbook Pro 15 2011 and tried everything except the cable so far. So likely that´s the problem. I see the same imprint on the bottom lid as illustrated where the cable connector have pressed against the bottom case.
    A design flaw there Apple. Could possibly a revised cable exist with a lower profile connector ? Anyway I ordered a ordinary one on Ebay let´s see how it goes.

  14. Replies
    1. Update - I had previously posted this as being successful (June 7 2015). About 1 month ago (November 2015) I started having the issue again. I think it happened only once or twice. Could've been something else. Then I had the logicboard replaced by Apple due to the GPU issue and am now having the trouble regularly again. I assume they gave me an older cable so I'll never know if the wifi/bluetooth cable is a good fix long term. Not sure if I want to try it again as the part costs about $50-60 with shipping to Canada. Going with USB wifi dongle (nano-sized/limited range) instead.

  15. BTW, I could only find a part with serial 821-1312-A for my 15" (different from above)
    It fit anyway but your own mileage may vary. Cheers.

  16. My 2011 15" macbook has similar issues although not quite to the extent listed in your blog. It simply connects to the network and then continues to spin "Looking for available" but the connection always seems weak and cuts in and out often. Do you think a replacement cable would help?

  17. There isn't much discussion about this issue anywhere else so despite all the spam comments I thought I'd provide some input in case it helps anyone. On my 13" Macbook Pro (Mid 2009), I will frequently lose wi-fi after maybe 30-60 minutes of use - or after just a couple of minutes if I start a large file download.

    I was laying back on a couch using my laptop when I first noticed the issue, and what I eventually discovered when I shifted positions (the laptop started getting hot, which is important - it takes 30-60 minutes for the issue to appear because it doesn't happen when it's cold) is that placing directed pressure on the bottom of the case, in the middle towards the back, actually solves the issue - the wi-fi comes back at full speed. I can watch this happen in real-time by starting a download and watching the speed as I press on it and then release the pressure (or simply watching a website struggling to load, and then coming through instantly when I put pressure on it).

    So, I'd suggest trying this - when you lose your wi-fi connection, make a fist with your hand and rest the computer on it, in the middle towards the back. And as a stop-gap solution if you desperately need to download something large (and don't have access to wired ethernet), you can rest the macbook on something like a bottle cap to get the directed pressure in the right spot - though I worry that doing that will cause more damage over time so it's really just a temporary solution. I mean, it's clearly a temporary solution anyway since it's super annoying to have it like that unbalanced.

    I am going to open the case and see if re-seating the cable works, but I suspect it probably won't in my case. It's my guess that if putting pressure on it *doesn't* work, then you may just need to re-seat the cable, but if pressure does work, the cable probably needs to be replaced. But, I'm not sure about that, YMMV.

  18. Took the laptop to an authorised Apple Repair Center. They did nothing. As it was an intermittent issue, they said that the wifi was working fine ... eapplelaptops.blogspot.com

  19. Great blog Thank you - been having exact same problems on my 2011 MacBook Pro 15" and been searching for solutions - just ordered a new cable - your efforts are greatly appreciated.Thanks for sharing.....

    Best Console Repair Shop | Laptop Repair Specialist In Manchester

  20. The wireless card would not connect to a specific SSID, so we figured it was a software issue. After checking all kinds of settings, it looked like we got it working. But when I returned the laptop to it's owner the problem reared it's ugly head. So, I found this article and replace the ribbon cable...the machine has been connecting properly ever since the ribbon cable was replaced! I was getting ready to replace the wireless card, glad I found this article first!!

  21. You rock!
    My son gave me a macbook pro 13 mid 2010 unusable because of freezing randomly every boot. As a curious I' tried removing the battery, new battery, clean install with disk repair, some osx 10.8, 10.9, 10.10 and 10.11, another disk, disabling hibernation, disabling wifi and nothing worked although disabling wifi give some relief. After reading your post I simply disconnect the wifi cable from the motherboard and no one could imagined: water turn into wine. Bingo! I also cleaned the tip of the connector and put it back. Since then not a single problem.
    Thanks a lot.
    Bruce Magnani

  22. Thank you very much for this article, problem solved without wifi card replacement!

  23. Wow - Just started having intermittent wi-fi issues with my late 2008 15" MBPro - After monitoring it with speedtest I thought it was just a weakening router. Then I moved the router next to my work area - before long started having the same issues, and a PC right next to the MAC was working fine. Thanks for sharing!

  24. Going to try this. Although I think mine happens when the mac is running hot, like when the fan kicks in. I was using my Macbook and the WiFi died, the fan was running, the bottom of the laptop was hot. Let it cool for 20 minutes and it came back on.

    When fan is not running, and laptop is cool, no issues at all. When Outlook/Spotlight, or something else is indexing, and the CPU gets hot and the fans kick in, this is when the WiFi dies.

    Hope the new cable works.

  25. I'm going to try this, is it difficult to replace the cable. I don't have a clue where to start. Thanks

  26. Whos the idiot spamming this blank atm card crap?