[ICOM] IC-821H TX problem

[Ekki Plicht (DF4OR)]

Hi all.

Since a while I experience a problem with my IC-821H. When keyed on 2m it goes 
to transmit, the needle of the meter swings to full level, but no output 
(checked with 2nd rx). This happens in SSB and CW, FM is ok. 

This goes on for a while, then it works normal again. Sometimes this condition 
holds for very long, usually only turning off for a longer while helps.

I had the unit for this very reason in service at Icom Europe a few years 
back. They said they couldn't really find an error and speculated it might be 
some capacitors in the Tx/Rx switching stage. The radio is now about 10 years 
old, has been in constant use and usually switched on all the time. So dried 
out capacitors might be a good hint, but I don't want to exchange randomly 
Cs, but would prefer to understand the problem more properly.

Any ideas where to start looking? I have the schematics here and access to the 
service manual as well.

73,
Ekki, DF4OR