Macbook Pro USB drives not detected

Question

Macbook Pro 10.7.5 isn't detecting USB flash drives. Six different USB flash drives. Preferences set to "auto-detect" and display external drives are not working. Have rebooted (soft and hard reboots), tried to reset the SMS by following the prescribed sequence: sleep mode --> restart --> shut down no change

Answer 1

Try USB Prober. It's installed with Apple's Developer tools, but you can also download it from this site: http://touch-base.com/documentation/USBMacProber.htm

If that doesn't work, it's probably a hardware issue.