USB Puzzling . . . Cooling Tray Connection

I need help understanding USB-C / USB-A interface. I thought I understood it, but that's not the case and hence I need some help.

I have a laptop with two USB-A ports on the left side and one USB-C port at the rear. I've verified all the port work by connecting external disc drives to them.

Normally, I connect a cooling fan tray, which the laptop site on top of, to one of the USB-A ports. This provides power to the three fans in the tray; only power is needed for the cooling fan tray (no other communication).

I want to move the cooling fan tray connection to the rear and use the USB-C port. I thought this was a very, very simple connection, but I've not been able to do it. I've purchased three different USB-C / USB-A cables, but when I've connected any of them directly to the C port and the fan's A port...nothing. The fans are not powered on.

I do have a Best Buy USB-C to USB-A 4 port hub that works....plug-in the USB-C plug and attach the cooling tray plugs to one of the 4 USB-A ports and the fans work fine. But, not when I use a direct cable.

What am I missing / not understanding....frustrating to be stumped by USB connection I thought was a simple "no brainer". Would appreciate you help. What cable do I need to buy to provide power to the fans via a USB-C port?

Many thanks.

Does the Best Buy USB-C to USB-A 4 port hub have it's own power supply? Could be the ports on the computer aren't supplying sufficient power, common with USB 2 [black] ports while USB 3 [blue] ports provide more.

No, the Best Buy USB-C to USB-A 4 port hub do NOT have a separate power supply.

fwshaw said:

No, the Best Buy USB-C to USB-A 4 port hub do NOT have a separate power supply.

Click to expand...

Some USB ports, of any flavor, don't supply power, or supply very little, as @Berton said.
It hasn't been standardized for some ridiculous reason.