To ensure your registered handsets receive
all the required updates, turn all of the
handsets off by holding the red button until
you hear a beep. Please leave them on the
side and avoid putting them back on charge.
Turn off the W53, leave for 30 seconds
and then turn it back on. Allow the bottom
2 lights on the W60B to go solid green before
turning the handsets back on one at a time.
Yealink W53 Set Up Guide