So I've been debugging as I get time my recently finished K2, and trying to find out why it's got no output.
Tonight I traced all of the DC voltage points in the troubleshooting guide, and found two anomolies, both of which are connected to one another. On pin 7 of U4, and also pin 1 of U5, I get 4.9V, and the manual says they should be 0V. My first thought was a solder bridge, but I see none. U4 is where there's a mod on the bottom side of the board. My thought now is that while adding that mod, I overheated U4 and opened up a path to pin 7 of 5V. Does that sound possible/reasonable/likely? Would that also cause my "no output" problem? These chips appear to be in the PLL circuit, so it seems if these were fried, I'd have frequency/VFO problems, yes? Since these two pins connect to each other, and nothing else, I don't see any other way for 5V to get in there. Or, am I chasing another ghost? :) Thanks for any ideas guys, you have all been very helpful and I really appreciate it. Jeff _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
