Geeetech

It still doesn't work. I've gotten another power supply from a desktop and nothing happens.

I can see the voltage input port clearly, but the 4 ports should be connected to power supply. Did you do that?

OK, now since you got reasonable voltage and power to the board, now try swapping the 2 ribbon cables on the LCD to try and wake that up. Motors won't do anything till you're able to tell it to.