Hi, not without a multimeter of some kind I'm afraid. You either need to check for 5V on both sides of it with the power on or check for low (0) ohms resistance across it with the power off.
Alternatively, you could bridge it with something (piece of wire, small pair of pliers) just to check. The fact that you get no leds flashing on the keyboard on boot is a giveaway though.
Either replace it or. as some other posters have suggested, get a PS2-USB converter for the keyboard you have or get a USB keyboard.
Good luck!