We need to kind of "help" the contacts settle back at their position to touch the amplifier contact.

I managed to do this using a long needle to tickle the contacts a little bit, just enough to let them snap back and make the circuit.

Caution: These contacts are tiny and sensitive. So, be very careful not to bend them too much. You can easily ruin the jack or make things worse. So, be very careful, and do not apply force. It is just about gentle tickling.

What we want to do is not actually bend a contact towards the other. We rather want to poke it gently, and let it snap back to the proper position.