So I'm having an issue with three rows out on my taf (using a seigecraft lamp test board here so the issue is on the board)...Checking the Tip 102's three are not lighting up on my logic probe. So when I go back to the 74LS74 I'm checking the outputs at the ones that are working to confirm against the three that are not right...I get to U10 pin 13, I get nothing. (although this is not control the transistor that's giving me a problem) Schematic shows pin 13 connected to pin 1 via board trace. I check all my other 74's and they're all connected (ohm/continuity check) and giving an output. So I had replaced these with sockets and now I'm thinking I screwed up the trace somehow and now I remove the socket again only to find that pin 13 goes nowhere...just simply a single trace on the board both sides? Anyone have any idea how this is? The lm339 in this circuit is an overvoltage cut off correct? How do I determine if its shutting off the 74LS74?