W520 USB 3.0 (blue) ports intermittent

[Arabian-Nights]

The two USB 3 ports on the left hand side of my W520 have become intermittent. When I first plug in a drive, they work for a few minutes only, then my external external HDD cannot be seen. The USB 2.0 port on the rear is OK.
Any suggestions?

[dr_st]

Are the problems just with the external hard drive? Is the drive USB 3.0? Have you tested other devices such as flash drives?

If the problems are specific to the drive, then I suspect the USB 3.0 ports simply do not deliver enough power for USB 3.0 hard drive. When connected to USB 2.0, the drive might take less power + if you use the yellow USB 2.0 port, then that port can deliver more power than standard USB.