I'm a newb. I completed the circuit board for the $50 Robot, but I don't have a multimeter or other testing supplies. When I attached a 5V power supply to the ground and the battery + pins, I got small sparks, but nothing happened. The LED did not light. I later (foolishly) tried attaching my 5V power supply directly to the soldered-in LED to see if it was breaking my circuit, and it lit for a split second then went out forever. I suppose I'll just start over, but are there any suggestions as to where I may have messed up the first time based on my vague description of the test?