Yealink SIP-T2 SERIES Administrator's Manual page 953

Factory reset can restore the original password. All custom settings will be overwritten
after reset.
The IP phone only uses logo file in DOB format, as the DOB format file has a high
compression ratio (the size of the uncompressed file compared to that of the
compressed file) and can be stored in smaller space. Tools for converting BMP format to
DOB format are available. For more information, refer to
File on page 221.
IP phones use the PoE preferentially.
If no lights appear on the IP phone when it is powered up, do one of the following:
Reboot your IP phone.

Replace the power adapter.

If the power indicator LED is on, the keypad is usable but the LCD screen is black, please
reboot your IP phone.
Troubleshooting
Customizing a Logo Template
931