Hey EvilMad,

I have tired to follow the instructions and have read over previous posts, especially:

http://www.evilmadscientist.com/forum/viewtopic.php?forum=14&showtopic=2800&highlight=column
http://www.evilmadscientist.com/forum/viewtopic.php?showtopic=2926

But I still seem to be stuck on the following problem. Column 23 does not seem to light up for me:
http://img710.imageshack.us/i/20100422174317.jpg/

I have checked the connections between the lines from U3 to the resistor and the transistor at Column 23 (this should be the line of the top side of the board coming from pin 22). I was shipped an extra transistor and replaced the transistor at Q23 and still nothing.

I then loaded peggy2_static and still nothing on col. 3. Any suggestions?

I apologize in advance; you must be tired of answering these kinds of questions

Hi Quasi,
Both of these forum posts that you link to are different from what's going on with your board. So, try not to pay too much attention to those solutions.

The transistors control which *rows* are active, they do not control the columns. So... it's a good thing that you didn't break anything replacing that transistor. (And, the reason that we include extra parts is generally because they tend to get mangled or lost-- not because they mysteriously don't work.)

Column 23 is controlled by pin 12 of U5. Your problem is *probably* at that location. It could also be a scratched or broken trace between that location and the column of the LED grid.

Thanks for the help. pin 12 just needed a bit more solder. Apparently, my problem fit into the 90% of assembly issues. Sorry to be a bother.

Actually, this is my favorite type of tech support. You described the problem clearly, I was able to tell you exactly where to look-- which probably saved you some time -- and the suggestion actually fixed it.