Sjoerd, Your AGC symptoms sound similar to some of what I found wrong with s/n 3641 when I bought it used. You can find a lot of details in the elecraft archive - (search for "low audio on K2 s/n 3641").
Among other problems, I had a leaky C10 cap in the AGC circuit, upsetting the AGC control circuit /AGCOFF. You might want to check there, to make sure there is no signal on pin U1-2. 73 de chris K6DBG _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com