JBL JR310BT / JR300BT push button for power

Hi, my daughter's headphones won't switch on anymore when pressing the power button.

• When opening the device and shorting the two pins of the power button, the device switches on.
• When measuring for connectivity with a DMM over the button pins, the DMM does not indicate a short when pressing the Power button. It does work for the Bluetooth button.
• I can hear the click when pressing the power button, so I believe the problem is withing the push button but not with the device mechanics.

Can someone help me out with the part number of the button? I have solder equipment available to do the repair, but I can't find the spare part anywhere.