Grandstream Networks DP750 Administration Manual page 109

4. Press "Yes" (left softkey) to confirm and the phone will reboot.
To cancel the Reset, press "No" (right softkey) instead.
Users also can perform factory reset using combo keys on DP720 during booting up prior it's fully booted,
to give DP720 the ability to recover from some extreme cases like self-reboot or stuck right after booted up.
Please refer to following procedure for DP720 factory reset using combo key:
1. Connect the USB cable and power off DP720.
2. Power on DP720 and wait for Green LED.
3. Press 3 times Central Key (OK/Selection Key) quickly after Green LED on.
4. Press Speaker Key (left bottom) first and then Mute Key (right bottom) after Red LED on.
5. DP720 LED will start blinking in 3 colors: Green, Red and Orange if factory reset successful
triggered.
6. Wait for about 1-3 minutes, the DP720 will boot up with setup wizard for initial language and date
format settings.
DP750/DP720 Administration Guide
Version 1.0.11.4
P a g e | 109