Can you get CW decoded on the LCD while transmitting?
If so, then that leaves one op-amp (and stuff connected to)....IC10A.
If CW doesn't decode (and the menu item is ENABLED), then
everything past the gain pot (Q7, IC10B, IC10A) is suspect. I'm pointing
out the active devices, not to point suspicion to them, but to broadly
point out the stages - all the parts associated with these stages are suspect.
You have an intermittent - a nasty thing to debug.
I might suspect the earphone jack area. If this thing is overheated during
soldering, it can distort and its spring pressure relaxed...the clearances
inside are tiny.