External HDD prob

[ro2124]

Been having a lot of trouble with external hard drives.
They only seem to work when connected into the laptop USB ports.
But I can't get them to work using a USB hub.
I know they need a power supply if using USB hub.
So I got hub with a power supply but still they will not show up on file manager, although they make the connected sound, when plugging it in.
I can't understand why, the USB power supply is rated at 20W 5V/4A.
I would have thought that is sufficient?.. but apparently not.
Do I need an even more powerful USB hub?
Any advice would be welcome.

 

[Bighorn]

If the HDDs are relatively new they may use USB 3 ports, both of my 4TB WD drives do but they also still require their own power supply, use the same 3.5" drives as in my Desktops. My 1TB WD MyPassports use USB 3 but don't need any other power, much more portable, use the same 2.5" drives as in Notebooks. For recognization issues the type of port used is important in that they are what is specified. Some USB 3 devices are backward to USB 2 ports. The device-end of cables don't usually interchange, different between USB 2 and USB 3.

Oops, intended to say this about the 2 types of drives, the pocketable like the MyPassport use 5V drives while the larger ones need both 5V and 12V, hence the need for their own power supply. The 'connecting' sound of the large ones just signals the connection, not the readiness.

I'm using a 2TB in a Desktop I took out of a portable case when the electronic interface in the case failed but the drive is still good.