Chosen Solution
I’ve run disk utility (First Aid button) on the external drive and there are no noted problems. After running First Aid, the “mount” button is still greyed out. I’ve tried restarting without any impact on the situation. I can plug my iPhone into both USB ports and it is recognized without problem. The external drive is automatically mounted and fully functional on my other Macbook. I have a second external drive on my other Macbook which works fine and plugged it into both problematic USB ports and does not mount. I have switched USB cables without any change to above described condition. That my iPhone is recognized without problem but not the external drive is confusing. Is there a way to reset USB ports or does anyone have another suggestions. My Macbook is from 2009 and I’m running OX-X El Capitan (10.11.6) Your time is greatly appreciated.
David have you tried other ports i dont know hon sorry i wasted your time sounds internal
OK I think I see the issue! Your 2009 system offers USB2 Type A ports unlike the newer 2011 and onward systems which offer USB3 Type A ports. For reference here’s the Type A sockets
USB2
USB3 Note the extra pins so depending on the device it maybe strictly USB3 as such it can’t communicate with your older MacBook Pro.
