[Yaesu] FT-840 power output problem

[Martin Sole]

Am looking at an FT-840 for a friend. Everything seems okay except for
power out. In CW mode, MOX on power increases to about 40 watts. Will
increase slightly beyond that but the signal then contains a degree of
'modulation' so my guess is it's going a spurious. My thinking is
probably the PA only half working, I can see about 0dBm out of the TX
drive point on the RF board, not sure if that's enough but it looks
clean.

Wonder if there is a known problem with the PA and if there are any neat
tricks to isolating the problem?

I have a user manual and the schematics but would appreciate a copy of
the TX set up info from the service manual if anyone has that
electronically available.

Martin
HS0ZED