Chosen Solution
My Mac Book Pro does not recognize external hard drives that show up on other Macs. It is not a software issue.
You’ll need to get a USB port tester to see if the port is offering up enough power USB Port tester You likely blew the fuse links. This can happen when you use the wrong power brick for the drive or other USB device you’ve plugged in. Also some HD’s need more power than what the older MacBook Pro’s offer so you need a dual USB cable. Another way of testing things as well as a stop gap is to get a powered USB hub plug your hub into your system and let the hubs power brink handle the power needs of the drive.
This will probably be the least technical solution possible. I had this problem recently and I took a dry toothbrush and ran it through the ports a bit. If that doesn’t help then the Port Tester would be the way to go!
