What happens when you change the plug for one that works, or get a new power lead cable and use that?
Short answer to your question; no, connecting a USB cable to a laptop that has no power will not work.
At the very least, the laptop's had drive needs power to spin up so that data can be extracted, but even then the two systems have to speak to each other. That means the laptop needs to be working properly.
There are other ways, but the easiest is to replace that plug.
The plug for my computer no longer works so I can't charge my battery and can't get power to it. I got a new computer but am wondering if I can transfer my old files to my new pc using a USB to USB cable. (In other words, will the USB cable be able to provide power so that I can copy my files?) If so, is there a specific type of cable I need to order? THANKS!!!