/diy/ - Do It Yourself

I got one of these external USB optical drives.

It comes with a "Y" cable in the box, one mini-USB on one end, 2 USB A on the other end, one is data, other is extra power because the drive consumes a lot of power. Now the original cable is broken and can't get a replacement because it's non-standard and I have to import one from china and risk it being a bad quality one yadda yadda...

I used several high-quality regular mini-USB wires but they last nothing until they become resistive enough that the drive resets when trying to spin-up the disc because it power-starves.

I was thinking about adding an external power input to hook it up to a wall power supply or one of those phone chargers (5V 1+A).

The plan is to add a diode to the original port to avoid the external PSU supplying a voltage to the computer (back feeding power to the computer's USB port). Now I was looking at the circuit inside the disc writer and what I found is that it has some kind of voltage sensing, maybe brown out protection and that makes it more difficult because of the circuit layout.

Should I connect that to the external supply point or keep it on the computer's USB?
I'll make a diagram of the original circuit and what I'm planning to do.