External drive will not power down

Hi GmaLab,

Thanks for posting.

Have you tried turning off the power at the wall? 

Power Share keeps the USB power on. When this option is set to Disabled, the USB PowerShare feature will be turned off and devices attached to the USB ports will not be on when the system is in a low power state or off.

Power States

S1 (powered on) - USB power is on by default with AC.
S3 (Standby) - Battery or AC.
S4/S5 (Hibernate/Powered down) - AC only.

Thank you Speed Step for your response.  The Inspiron 3252 I have is a referred to as a small tower.  It appears to me to be based of the internal electronics of one of the Inspiron Laptops.  It does not use a battery for power, strictly 110 AC which your suggestion implies.  I can not find a On Board Devices / USB PowerShare option as part of the Settings options for the machine I have.  Thank you, however,  for your suggestion and interest .  GmaLab

Reboot and immediately press F2 to open BIOS setup.

Look for a PowerShare option in BIOS. Note: Not all PC models have this option.

Change that option to Disabled or uncheck the box, assuming you have the PowerShare option. Be sure to save the change when you exit setup. Do NOT make any other changes in BIOS setup.

See if that solves the problem...

Thank you for your suggestion.  The BIOS on my machine is DELL Inc. 2.11.1, 6/21/2017.  Unfortunately I find no Power Share option  The Power option available relates to sleep mode, etc of the computer.  USB options will enable or disable front and rear ports.  Thanks again for the suggestion.  GmaLab