Would definitively happen if you or the person who owned the S1 before you did pen modding.
I didn't know what this was so some googling and took a look at the board and the resistors R3, R66, R38, R52 were all colored black.
I just took an eraser to one blade and that seemed to do the trick!
http://imgur.com/bc6BsjfThank you for the speedy reply!!
*nod* Make sense. Running them undervolted is a very good though. You can cut the consumption in more than half and only lose 25% hashrate or so. Keep that in mind if you get more, since just the saving on PSU capacity is very good, even when you have free electricity.