[Elecraft] K3 Seems to have Failed on TX

[Ian Greenshields]

My K3/100 seems to have died on TX.

It's worked fine for many years, but now on TX with any mode and band,
there is no output power.

The rig switches to TX, but the display shows 0W, and there of no RF from
the antenna socket. Changing the power control briefly shows the set power,
but then the display return to 0W and '--' where the SWR is normally shown.

This occurs both above and below the 12W power threshold (where the 100W PA
switches in).

The receiver and UI/firmware all seem to work fine.

I've checked the obvious sillies like TX test not on and TX inhibit not set.

I've also reinstalled the latest firmware and reverted to a known good
configuration file, but the problem still persists.

It feels like there may be failure some where in the driver stages, but
does anyone have any ideas for what the issue might be and hopefully some
pointers to track it down and fix?

It's an early unit, S/N 180, if that helps.

TIA and 73,
Ian G4FSU