Seagate Expansion drive - problem with power off function.

I have an (intermittent) issue with my Seagate Expansion drive in which it continues to remain powered (disk spinning) when the PC has been shutdown. When this happens I find the drive is also lost (not visible) in Windows (File Explorer). I have to turn the power off at the wall to correct the issue.

I'm unsure whether this might be a Windows (software) issue or a hardware issue with the drive. Do external drives have a built in mechanism to control the powering down of the drive with Windows or is controlled exclusively by Windows and the USB cable the external drive is connected to? What could be my problem?

Some PCs have USB ports that remain powered even after the PC has been shut down. This is for the convenience of being able to charge devices and phones without having to turn the PC on.

You can try and find an USB port that is not constantly powered, or you can go into your BIOS settings to see if there is a setting that will allow you to turn that feature off.

TV2 said:

Some PCs have USB ports that remain powered even after the PC has been shut down. This is for the convenience of being able to charge devices and phones without having to turn the PC on.

You can try and find an USB port that is not constantly powered, or you can go into your BIOS settings to see if there is a setting that will allow you to turn that feature off.

The drive staying powered on is intermittent, 98% of time the external drive does powers down with the PC when it's put to sleep or shutdown. This doesn't seem consistent with power setting being either on or off....

It would be worth your time to check anyway. At the very least to eliminate it as a possibility.

Adding to what TV2 said, the motherboards of the last upteen years are continuously powered even when off until pulling out the power cord. The On|Off switch is not directly connected to the power supply like with the old AT computers/motherboards, the ATX boards control things.

As mentioned, you need to go into the BIOS and turn off the option which keeps the USB ports powered on. Else turn off the PC at the mains switch or using the PSU switch.

Thanks for the replies. However I still think this is an intermittent problem as apposed to a setting being either on or off. If it was a setting that was turned on the drive would remain powered every time I put the computer to sleep or shut it down. As I mentioned 98% of time the external drive does fully power off when the computer is put to sleep or shutdown. It's the other 2% that it will randomly remain powered on, even when the PSU switch has been turned off...

The external drive is powered with an AC adapter at the wall, or in my case UPS and I wonder if the issue could lie there. I will check for BIOS settings again but...

Be careful on the UPS, have seen some in the past that had one outlet that could be controlled by a device and when that device was turned off all the other outlets also turned off.

My BIOS only offers an always on power for the USB-C plugs and it has to be enabled which it is not. The external drive is on a USB-A port. Today the external drive lost it's connection to Windows again i.e it was not visible in File Explorer. Re-plugging the drives USB cable does not re-detect the drive, however pulling the AC cable from drive and re-plugging it re-detects the drive in Windows. Is this an AC power issue? UPS issue? USB cable issue?

It is sounding more like a detection problem.
External hard disks are normally used as an occasional extra storage source. You plug them in when you need them and disconnect them when you are done. They are usually not always on - always connected.

The way this is supposed to work on a powered external storage device is that it needs the AC power to run the hard disk and it uses the 5v USB power detection to switch it on or off. This is simple when the PC is already on and you connect the external. Windows detects the USB connection, the external detects the power on signal and everything starts up.

When the external is always connected it could complicate things. That may be the source of the problem.
When you disconnect the AC power and then plug it back in you are basically "rebooting" the external. Since it connects and everything works then that indicates that there is nothing wrong with the hardware.
It is more likely to be due to problems related to the PC starting, Windows starting, and the external starting all at the same time.

Unless you keep your PC always on. Do you?