[Elecraft] K2 problem: no tx output on 15 and 17m

[Nick Henwood]

Any advice please?   My K2 suddenly lost tx output on 15 and 17 (actually still a tiny amount - less than a watt). Still receiving OK on those bands. I removed the 100w amp and the problem relates to the K2 barefoot. There is common circuitry on these bands - any suggestions where to start checking pl? The K2 is still working OK on all other bands.
73 Nick G3RWF