I recently had to replace the caddy for my external HD. I was successfully using a 5m USB mini to USB A cable to transfer data between the HD and my laptop (Win 7 64).
The new caddy has a USB A socket, so I bought a 3m USB A to USB A cable. The caddy has its own power supply. When I plug the cable in to my laptop, nothing happens. Device Manager says there's an unknown device under USB controllers. The disk doesn't sound like it's initialising.
I tried the cable with a 2.5" external HD, too. The result is the same.
Both HD caddies work with a much shorter (30cm?) cable.
Thinking the cable was faulty, I ordered a replacement. Again, the same results, so I'm thinking it's a problem with that batch of cables OR my laptop OR the cable type.
I tried the cable with another laptop and the caddies. Same results, which seems to rule out my laptop.
Given that the Device Manager seems to recognise something when the caddy is attached via the cable, I'm uncertain of a faulty batch, so could there be a problem with the type of cable I'm using?