If a two-pin cable slips out easily or the music cuts out when it moves, stop relying on the connection until you know what is loose. A detachable earphone can be lost or damaged if the cable no longer holds it securely.

Is the plug loose, or is the socket moving?

Disconnect from the source and inspect the joint under good light. The cable plug moving in the socket is different from the socket itself moving inside the shell. Do not rock it forcefully to demonstrate the problem. If the socket moves in the shell, request service rather than trying to secure it from outside.

Rule out the wrong cable

Check the original model specification and compare the replacement with the original cable. Similar-looking two-pin plugs can differ in pin dimensions, housing shape and insertion depth. A plug that stops against the housing before the pins seat is not necessarily a worn socket.

If you have one confirmed-compatible, undamaged spare cable, a careful comparison may help. If only one cable is loose, that cable is a suspect. If multiple approved cables are loose in the same socket, the socket needs assessment. Do not keep cycling through many cables or force a tighter one in.

Do not spread the pins to tighten the fit

Bending pins outward can stress them, damage the socket or make later removal harder. Do not use larger pins as a tightening method. Avoid glue, nail polish, foil and conductive liquids around the contacts. A home-made shim may hide the symptom while creating another problem.

What can I do immediately?

Stop wearing the earphones where a detached shell could be lost.
Store the shell and cable safely and avoid side loads on the joint.
Take clear photos showing the plug and socket without dismantling the shell.
Report whether the issue affects the original cable, a replacement or both.
Ask support whether cable replacement or socket service is appropriate.

Does looseness always mean the earphone is ruined?

No. The cable may be the replaceable part, but diagnosis comes first. Warranty coverage depends on the applicable terms and inspection; do not assume every loose connector is either normal wear or a manufacturing defect.

Contact TINHIFI support and review the warranty policy. Check the connector guide before buying another cable.

Buying a replacement? Check QDC versus standard 2-pin fit first.

Illustration: generated editorial artwork, not a photograph of a specific TINHIFI model.