December 14, 2012 at 6:07 pm #21049
>My son is extremely disappointed.
I would think that this would be good motivation for you to look a little harder and figure out what the problem is. This is a very simple circuit, and there isn’t much that can go wrong.
– If it was left on for more than a few tens of seconds with the pins connected together, it may have drained the batteries pretty well. Try swapping in a new set, to see if that makes a difference. If the circuit was getting hot when it was turned on previously, it’s also possible that there’s actual damage to the circuit board or components.
– Check very carefully to make sure that there are no remaining “solder bridges” or other short circuits. If you have other solder joints that look blobby, cracked, or dry, you should probably touch those up again. If you like, you could send us a picture of the bottom side of the board, and we could help you find what else might be wrong.
– Double check that the chip is inserted with the correct orientation, and that the battery wires are soldered with the correct polarity, too.
– If you have an extra LED in your kit, you can touch the leads across the leads of the LEDs on your circuit board, to see if it lights up. If it does, you may have inserted the LEDs backwards.
Please let me know how it goes.