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Model A1311 / Mid 2011 / 2.5 & 2.7 GHz Core i5 or 2.8 GHz Core i7 Processor

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2 of my USB ports have only power but no data

2011 21.5” iMac (iMac12,1) with a i7 CPU and running macOS High Sierra (10.13.6)

I'm pretty stumped by this...

2 of my USB ports have stopped working, but not completely... if a flash drive is plugged in it'll briefly light up before turning back off and not showing up at all, USB devices which need a USB port to charge work fine but no external drives or devices, and the other 2 ports still work completely fine

What I've tried already:

  • Restarting
  • Resetting PRAM
  • Resetting SMC
  • Checking software update
  • Reinstalling macOS
  • Apple hardware test (hold D at startup) running the Extended apple hardware test

Please does anyone have a suggestion? thank you in advance

Answer this question I have this problem too

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This sounds like you have a bad USB hub chip. Here’s a breakdown of the external ports

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So as you can see there are two hubs! Ports A & C are served by Hub 1 and Ports B & D served by Hub 2. At this point you’ll need to figure out which hub circuit has failed. Both are USB Hub Controller USB2514-AEZG QFN package.

Hub-1 U3500 and Hub-2 U3600

It might be a cold solder joint or the chip its self has failed.

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well this pretty much confirms my worst suspicions... and makes perfect sense now too since i just checked and yep SD card reader isn't working either

so why wouldn't even the extended apple hardware test pick this up? and even with this failed the ports would still have power flowing to them? i also feel like replacement of the logic board will be the only thing that can remedy this :(

thank you for the reply and the knowledge, i always love learning more about my devices


Let's not throw the baby out with the wash water! This is repairable!

While it maybe beyond your skills set and what you have for tools, I'm sure you can find someone with the skills and needed tools locally.

Where do you live? Country and nearest city.


right outside of New York on Long Island (officially Manhasset)... in May 2014 me and 2 friends did perform the dual hard drive kit install based off the guide on this site, that was some nerve racking stuff lol but so worth it for the added speed and response (and an extra 240gb never hurts)

i really don't have any soldering skills or experience though and frankly don't ever want to have to take out that logic board on my own again... parts for this computer are getting harder to find and i'd much rather the liability be in someone else's hands, but depending on what's involved maybe i'd be willing to entertain the possibility


@Stroock6394 - Can you get your self to the downtown NY? See if Louis can fix your system: Rossmann Computer repair 141 W 27th St NY


@danj sure i can, thanks for the info!


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