MacBook Pro USB port problem...

Somewhere between 10.4.11 and 10.5.2, this problem has been fixed for me. Software related.

I have a similar issue. 1 week old MacBook Pro (late 2007 version) 15" with 2.2GHz.

Both ports work fine to power USB thumb drive or my Logitech Vx Nano mouse. But the left port that is near power connector intermittently loses power for USB thumb/flash drives. I lost my whole data yesterday due to it randomly disabling power to my drive while i had its TrueCrypt volume mounted. If you eject a TrueCrypt volume without proper un-mount you can lose data.....i lost it all 😟

Beware of the left USB port on MacBook Pro. I am running 10.5.2 with all the latest updates and still happens intermittenly so I now only use this port for my Vx Nano mouse.

I have the exact same problem with my MBP (left USB port doesn't seem to be working at all... even the apple keyboard doesn't work with it now). Am pretty sure that it wasn't always this way...

Am also using the late-2007 model.. is that was everyone here is using?

This seems to differ a bit from what the rest of you are experiencing, but I'll put it in here anyway:

I have a new 15" MBP and I use it in conjunction with an X-Rite DTP70 Spectrophotometer. The DTP 70 has blown a circuit board twice in the last month when I've plugged it into my MBP USB port. I use the device extensively with PC workstations and when necessary, with my Mac. I didn't make the connection that the MBP was damaging the spectro until this last time I plugged it into the MacBook Pro and blew it up for the second time. Is it possible there is a grounding issue with the MBP USB ports? How the heck would you go about trying to confirm a problem like this?

I also have two iPods which seem to be unfazed by this problem...

I've just run into this very same issue.

I bought myself a 2.5" External USB2.0 SATA drive which I've been using for the past two days to test out Time Machine on Leopard.

About 20 minutes ago my machine rebooted and then lost all connection to the drive which I've been running in the left-hand port. I thought that the drive had died and tested it in another machine - works fine... so I plugged it into my right-hand port and sure enough - all works.

When I plug it into the left, I get the same under-powered clicking noises from the drive others have experienced here but yet USB flash drives power and mount fine.

Weird that so many people here have had issues with the left port all along yet mine has been working up until now 😟

I have a slightly different variation on this problem. I have a brand new Macbook Pro, 2.5 Ghz, 17-inch, that came with the stock 2 GB of RAM. I ordered two 2 GB Ram modules so I could up the memory to 4 GB of RAM and found that after installing the 4 GB of RAM, the left two USB ports quit working entirely. They would not even work with a USB mouse.

Uninstalling the 4 GB of RAM and going back to the factory RAM solved the problem, so I am contacting the folks I got the RAM from for a replacement.

Will report on how it goes.

Wow, didn't realize so many other people were having problems with their left side USB ports like me. My mouse works on the left side, but my iPod Nano won't, nor powered external HDDs. Seems to work at first when I power up the machine, but after it's hot, it fails. To make things worse, having a failed external device on the left side, screws up the right side USB too, requiring a reboot. Grrrrr.

I should not be having these sort of issues with a $3500 premium work-horse of a machine...

Hey,
i have now a brand new MBP and have a Problem with the left side USB-Port. So i called the Apple Support, and they said to me, taht i must restart or something with the electric circle.
Pull the battery out and the cable, and pull 10 seconds the power button. After that my apple keyboard function on the left side.
The next day no USB devices function on this side. After a new call to the apple support i received a new macbook pro. But now, the same problem.
Monday a new call to Apple Support.

my problem is with the right USB port and using the adapter to connect to a dialup. Works fine using the left one but disconnects after 3-4 minutes using the right one.

I got my left-hand MacBook Pro USB card replaced yesterday and so far it has been working fine. I did however notice previously as someone else mentioned, it doesn't always fail but tends to be once the machine has been running for a while.

I'm going to leave it running all day today and see if the left-hand USB port gives out again.

To those who are having repair work done, is replacing the left-side USB able to be done on-site at an Apple Genius Bar, or did you have to part with your notebook? I regularly see my external (AC powered) USB HD disconnect when connected via the left port during read/write operations. I even attached a powered USB hub to that side, when that failed. Still no joy. I can load up every peripheral I've got on the right-side though, on the powered USB hub, and it's fine.

If I try connecting my iPhone to the left port, it won't even stay connected long enough to sync. Seems like something I'd like to get fixed, if it won't mean having to mail my MBP in.

I heard on Mac Break Weekly that one of the guys was having audio problems from some USB ports and not others. Apparently the left USB devices in the MBP17 come off of an internal USB hub and the right one is a direct USB port. Not sure if its the same with the MBP15, but I thought it was interesting.

I had a local Apple reseller change out internal hard drives last week.
the new larger hard drive (OWC On-The-Go) worked just fine booting off the left USB ports on my MacBook Pro using buss power only.
Now the old internal is mounted in the OWC box and after attempting a reboot from the same port/ same cable / same OWC box...when using buss power..the drive clicks & clanks and refuses to start up the computer. I can switch to the right USB port (next to the firewire ports) and it boots up just fine on buss power.
When I use the external power adapter, I can boot up the system using the left USB port....So I am now convinced that there is a power difference on these USB ports. Don't know why the 200 gb drive boots and the older 100 gb doesn't....but
such is life....As long as one works, I'm ok.
I wonder if there's a better USB cable out there with less wire resistance that might make a difference. The USB ports on the left usually do the printing & wireless tranzport connection...I plug my Pace dongle on the right USB port. I can use this older drive using the SATA connection....it's just that I'm wanting a way to use Diskwarrior if something goes aray....SATA (Tempo Express 34) won't let you boot up a system externally..well not yet...who knows about future hardware releases will bring. I'm not ranting..just trying to understand what's going on.
<Edited by Moderator>
Thanks !
MacBook Pro 17, 2 GB RAM, OSX 10.4.11

Hi all,

Just sharing a bit of my experience. I tried to connect a Midi USB cable to my MBP and it just can't get connected. I tried the same cable with my iBook G4 and its perfectly fine. I keep searching for the answer through the forum and tried the all methods including reinstall everything but failed.

Finally, I tried to connect it through a USB Hub and it finally works. I don't know the reason why but another way to try if you have similar problems.

Ok I figured something out here ! I have had this 'left USB port' issue with my MBP recently, and it only happened after trying to use a SUB-Serial converter in the left USB port with Windows (Bootcamp).
I got an error message saying that there was a malfunction with the device, and subsequently, the Windows Device Manager said that "No drivers were installed for this device". After seeing that the port sends power to devices but would not read them, and reading of some issues with Leopard and hardware, I decided to re-install OS X 10.4 Tiger. That did the trick, and the drive is reading devices normally again.
Leopard has apparently had quite a few issues with onboard hardware, and has had a few firmware upgrades, but this UBS port issue could well be software (driver) oriented. Those of you who have Tiger, could try a clean re-install after backing up all you settings and info, try the left port, then upgrading to Leopard again. If you only have Leopard, then perhaps try a clean re-install of Leopard before further upgrading to the latest version.
See what happens.