Jack Cable Wobbles – Unreliable Connection
A wobbly jack plug is usually caused by bent contacts, oxidation, or a worn connector. Clean the plug with a dry cloth or a small amount of contact spray suitable for electronics – never use water. Check the socket on the instrument or amplifier: sometimes it has simply come loose and can be tightened from the inside with a suitable screwdriver. If the plug itself is bent or the cable jacket is torn, replace the cable – replacements are cheap and widely available. Taping it up as a temporary fix is not a lasting solution.