[Elecraft] K1 + 4 Band Filter Board - Problem - No TX on 2 bands but RX ok

[M0DHP]

Hi
 
Would appreciate any advice on this problem.  4-band received alignment was
OK; I got a good peak on all bands and receive from an antenna is working ok
on all bands.  On 4-band transmitter alignment, I get 2W output on 7MHz and
10MHz but virtually zero output on 14MHz and 21MHz.  Does the fact that RX
is ok but not TX help localise the problem to a particular part of the
filter board?
 
Thanks
 
Ray
M0DHP