[amsat-bb] TS2000 Birdie 436.795

I am a newbie to satellites. I have only worked the FM birds using handie talkies and arrow antenna. I wanted to start working in doors with my TS-2000. On SO-50 downlink 436.795 it has a bad birdie that wipes everything. Full squelch will not stop it. I have disconnected the antenna and still there. On other radios it is not there, so cannot be RFI. Has anyone ever heard of TS-2000s that have this? Any ideas of something that can be done to fix? Even sending it in to Kenwood Service. Cannot work SO-50 with it this way.  TNX 73  Mike K4MIA