I bought 2 WD My Book Essential 3TB drives.
Both of drives USB are directly connected to Mac mini Intel Core 2 Duo. No USB hubs.
One of drive cannot turn off by the power button.
Unplug USB cable or unplug AC adapter cable or shut down Mac Mini is the only way to power down the drive.
Even if I unmount it, I have to keep turning on its power while I use Mac. The power button does not react.
The other dive is fine. I can turn on/off by the power button.
So I can turn it off when I unmount it. It’s not going to turn on a power or automatically mount even if I restart Mac until press the power button myself.
Both of drives are the same model. same formatting, using under the same condition.
I have no idea what is the difference.
I’ve been trying to reformatt and partition by Disk Utility and WD SmartWare.
Exchange USB cable, AC adapter… etc But the power button does not react.
I’m glad if you can let me know how to resolve the power button problem.