After comparing the new solder joints to the ones I was making with the old iron, I decided to start completely over with the LED Binary Calculator. This time I used DIP sockets and new protoboard I was able to buy when I bought the new soldering stuff. This protoboard is 25 holes wide which is really convenient since each of the eight LEDs needs three holes width. There were also just enough of the old red LEDs I was using before to start over with. The solder didn't take to them very well at the beginning so I had to scrape off a lot of the coating that had formed on it. Because I didn't have a battery holder, I soldered on an 8 pin DIP socket to use as a power connector. I taped wires to a CR2032 battery and I stick the ends into the socket for power.