This is only applicable to SIP phone series including SIP-T42U, SIP-T43U, SIP-T46U, SIP-T48U,
SIP-T57W, SIP-T54W, SIP-T53W, SIP-T53, SIP-T53C, and VP59.
Procedures
Unplug the phone from power
Long press (Speakerphone key) and reconnect the power adapter to trigger the recovery
mode. Do not release until the recovery mode wizard appears on the phone LCD screen.
Press 1 to run the backup system.