I'll add to Brian's comments that it does not always require a burr to
produce the short.
In some KX1s either the head of the screw is a tiny bit smaller or the hole
is a tiny bit larger, allowing the beveled screw head to reach through the
hole in the cover and thermal-conducting pad and touch the metal tab on the
transistor, causing a short.
I fixed mine long, long ago by adding a second thermal-conducting pad.
Still, I'm very careful to check for a short whenever I reassemble it. But
in dozens of disassembly/reassembly operations it's never been shorted.
Others, with slightly smaller case holes or screws with a slightly bigger
head never had the problem. They were unable to create a short, even when
trying.
The nylon screw is the really foolproof solution. That's why they are
supplied with all current KX1s.
Ron AC7AC
-----Original Message-----
Hi, Paul!
Sounds like a tiny metal burr is shorting the case of Q6 to ground.
These are almost always at the screw hole. Check the following:
1. Make sure the screw itself is plastic; Elecraft will send you a
new one free if it isn't.
2. Pull off the insulated pad and use an Xacto knife from the inside
of the cover to "circle" (swirl around at a 45 deg angle) the Q6
mounting hole and remove any burrs.
3. Using fine sandpaper, sand the area inside the case that the
insulated pad covers to ensure it is perfectly flat, especially
around the screw hole.
Replace the insulated pad and reassemble. Very smart of you to use an
ohm meter to alert you of potential smoke inhalation during power-up.
Brian - W6FVI
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