Be sure that you are using a TRS plug that has standard dimensions. Nonstandard plugs can connect improperly and cause these symptoms.Here are the dimensions:Shoulder of the 1/4" TRS plug fits against outside of plastic threaded housing.Depth of plastic threaded housing is 9.35mm.Distance to first contact from inner edge of housing is 4.25mm.This means that the total distance from the outside of the housing to the first ("S") contact is 13.60mm.The next contact is 6.35mm away from the first contact.This means that the total distance from the outside of the housing to the second ("R") contact is 19.95mm.The next contact is another 6.35mm farther from the shoulder.This means that the total distance from the outside of the housing to the final ("T") contact is 26.3mm.