Hasbro wiring issue

[Coz]

Hello there. I have a 2010 sound card from a bladebuilders darth Vader but for some reason if I connect the 5w led to a positive and the negative to the led neg on the board, the 5w led comes on very dim. With or without the lightsaber on. But the led fitted to the board works as it should running with the std 3 aaa setup 4.5v is there a problem with the board or is there a way to get round this.thank you