SE-S084F dies when closed

Got this with no box no info, though I now gather that it should have a USB Y cable for extra power.

Plugged it into a USB3 port which is supposed to give more power, but maybe that only happens with a USB3 cable?

When open, it’s detected, closed, with or without a disk, it goes away (light blinks).

In the meantime, only other thing I can think of is to find the powered hub that I got ages ago, as that might not enforce power limits as tightly - don’t really want to go buying a Y cable if the drive is no good