RE: Lets hear about your Thunder Tiger Neptune SB-1.
Have patience it will be fixed,check the cristals make sure there both the same and pluged in a clean sucket as corrotion offen gets in there.
Try also a new set if the above look good and no change,all I did was to install the antena in a more horizontal web and circular way as originaly done see the pics.Also check each and every servo if there is one bad it will behave like this as well.Check all radio connections.
Let me know your findings and will go from there Dave