I'm using Mid 2014, Retina, 13-inch, Macbook Pro. I noticed that my right USB Port is not reading my 1 TB WD External HD but able to use mouse. How to fix it?
MacBook Pro (Retina, 13-inch, Mid 2014), OS X Yosemite (10.10.3), null
What is the status with the other USB port? If it is different, then make an Apple store genius bar appointment for a FREE evaluation. You then have a hardware problem. If it is the same, then the WD drive is suspect.
Ciao.
My left USB port is working fine with my External HD, only the right one have this problem. 😟
I inserted my 32gb flash drive and it worked in both USB ports, my 1TB WD Elements works fine with my PC and my dad's laptop so it doesn't have a problem. but when I'm using it with my macbook pro it only works in the left USB port.
I wonder if the right port is providing too little power, external disks often require more power than a USB flash drive.
Plug in the disk & view the System Information…
Apple menu > hold alt on the keyboard, select 'System Information'.
Select USB in the Hardware section. Find the device that tallies to the WD Elements, see the values for the Current Available (mA): and Current Required (mA):
Compare between the right & left port. NOTE, you will want to refresh the report when swapping ports, use the 'File Menu > Refresh' to do that.
Left (SuperSpeed Bus) Current Available 900 (mA) equivalent to 3.0 USB
Right (Hi-Speed Bus) Current Available 500 (mA) equivalent to 2.0 USB
both of them should have 900 (mA) since both of them are 3.0 USB 😟
Connect the drive & see what it wants to suck out of the Mac, it looks like you might have a reason for the failure to appear.
I'd try an SMC & NVRAM reset for the heck of it & then contact Apple for help.
How to Reset NVRAM on your Mac - Apple Support
Resetting the System Management Controller (SMC) on your Mac - Apple Support
My right USB port totally will not read my external hard drive.
My left USB port is starting to malfunction as well sometimes it works sometimes no, I have to replug or restart before HD shows up.
Manage to make it work and the readings for the left USB port:
Current Available (mA): 900
Current Required (mA): 896
It make total sense on why my right port won't read it because the required mA for external drive is 896 and available for right port is only 500.
Macbook pro retina display should have 3.0 USB ports, dunno why I only have 1 port with 900 mA.
I will visit an apple store nearby and check if other macbook pro have the same as mine.
I tried many things with my laptop PRAM, SMC, recovery mode repair, safe mode repair, updated OS X 10.10.3, Reformat HD.
There is totally nothing wrong with my external hard drive, I'm using it with my PC and tried it with my dad's laptop and it works fine. I'm using WD Elements 1TB
According to the fount of knowledge that is Wikipedia…
https://en.wikipedia.org/wiki/USB
As with previous USB versions, USB 3.0 ports come in low-power and high-power variants, providing 150 mA and 900 mA respectively, while simultaneously transmitting data at SuperSpeed rates.[25] Additionally, there is a Battery Charging Specification (Version 1.2 – December 2010), which increases the power handling capability to 1.5 A but does not allow concurrent data transmission.
It doesn't make sense to me that a 'low power' USB port would output 500ma unless it was working in USB2 mode.
A unit load is defined as 100 mA in USB 1.x and 2.0, and 150 mA in USB 3.0. A device may draw a maximum of five unit loads (500 mA) from a port in USB 1.x and 2.0, or six unit loads (900 mA) in USB 3.0.
You may want to get the genius to confirm the spec for both ports if you go along to a store, I guess they may have limitations.
I would also boot into recovery mode just to see if the disk pops up in Disk Utility via both ports - that could indicate the port is being rendered useless by the OS.
Apologies, you appear to have tried that already.
I have a mid-2014 15" MBPr with the exact same thing happening. External HD working on left, not on right. USB Thumb drives work on both. External wired mouse works on both.
Any update on this? Did you ever take it into an Apple Store ?
Have you looked in System information…
Apple menu > hold alt on the keyboard, select 'System Information'.
Look under USB & compare the information when the disk is connected to each port.
I don't know the specs of your Mac, occasionally some computers have ports that are a different spec, so you should confirm what version of USB the disk is using. Take it to an Apple store if you want free help, obviously you'll need to pay for any repair if there is no warranty, but the genuis bar should tell you what the Mac is capable of.
Right USB Port not reading External HD
