[Elecraft] Icom 735 inquiry

[rlpend]

This radio, which I purchased new and have not modified, worked fine 
six months ago. Recently I discovered that it receives normally on all 
bands, the LCD functions normally, and the CW sidetone is OK , but it 
will transmit only on AM and FM.  On SSB and CW the power output meter 
doesn't show "power out" and my field strength meter needle doesn't 
move. However the fan does operate and the Icom power supply becomes 
slightly warm when I attempt to transmit into the dummy load in these 
latter two modes. This state of affairs is the same into the antenna 
(when I discovered the problem) and into a dummy load. Years ago Icom 
replace the power transistors when it would not transmit, but I believe 
this failure was on all modes.

Any ideas where to look for the problem?

I am not an engineer or electronics technician, but have built many 
kits. Any suggestions about what I can try before sending it away would 
be appreciated.

Bob N5JYW