Register the Handset with the Base Station

1. On the DP750 Base station, press and hold the Radio/Page button for about 7 seconds until the radio LED starts blinking; or, access web UI > Status > DECT Status and press the Subscribe button.
2. On DP720, Press "Menu" 
3. Use the arrow keys to reach > Settings > Registration.
4. Navigate to Register, then press "Select" while the DP750 Radio icon blinks.
5. Select the corresponding base, and then press "Subscribe".
6. The DP720 handset will display Easy Pairing on the LCD and play an audible buzz when subscribed.

Checking Base Station IP address

1. Press "Menu".
2. Use the arrow keys to reach > Settings > Info.
3. Press the "Select" softkey to display the Info page. Browse the screen to find the IP address, subnet mask, and default gateway information for your DP750.

Changing the Base PIN

1. Press "Menu" 
2. Use the arrow keys to reach > Settings > System Settings. 
3. Enter the current base PIN code (Default is 0000).
4. Enter the desired base code PIN.
5. Press the "Save" softkey to confirm.

Handset Not Ringing? Troubleshooting Steps

If incoming calls aren't ringing on the DP720 handset:

A. Ensure the handset is adequately registered:

If the battery icon or handset name is not displayed, the handset may not be subscribed. Try re-registering. 

B. Verify firmware:

Outdated firmware might cause feature malfunctions. Update via a registered DP720:

Menu → Settings → Firmware Upgrade—or via the DP750 Web UI. 

Grandstream DP750 User Guide 

C. Factory reset & re-register:

Some users resolved ringing issues by factory resetting the device, upgrading firmware, and re-registering. 

D. Check call routing and SIP registration:

Use the DP750 Web UI to confirm SIP accounts are assigned correctly under DECT → SIP Account Settings. Ensure the HS Mode is pointing to the correct handset. 

Monitor the registration status via Status → Account Status → SIP Registration. 

E. Basic troubleshooting:

Make sure batteries are charged and inserted correctly.

Confirm the handset is powered on (press and hold the Power key if needed).