[Elecraft] Debugging no TX on K2

[Jeff Kinzli]

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