2.Plug the adapter into the domestic power supply.
Plug!
3
Add and register a doorbell
Make sure you plug in AC power before pairing it to the telephone base.
You can add another new doorbell (purchased separately) to your IS7121 telephone system. This telephone system accommodates up to two doorbells.
Each new doorbell must be paired to the telephone base before use.
1. | Press and hold /FIND HANDSET |
| on the telephone base for about four |
| seconds until the IN USE light turns on. |
2. | Press and hold /DOORBELL for |
| about 10 seconds until the doorbell |
| light flashes slowly. The doorbell light turns |
| on and you hear a confirmation tone from |
| the doorbell when registration completes. |
| It takes about 60 seconds to complete the |
| registration process. |
If you want to replace a doorbell, or reassign the designated doorbell number of a registered doorbell, you must deregister all system devices and then register each handset/doorbell individually.
Make sure you plug in AC power for the doorbells before deregistration.
To deregister all handsets and doorbells:
1.Press and hold 
/FIND HANDSET on the telephone base for about 10 seconds until the IN USE light flashes.
2.Immediately press 
/FIND HANDSET again. You must press 
/FIND HANDSET while the IN USE light is still flashing. The IN USE light flashes for about five seconds.
3.All handsets show Put handset on BASE to register and all doorbell lights flash quickly. The deregistration process takes about 10 seconds to complete.
To register the handset(s) and/or doorbell(s) to the telephone base again, follow the registration instructions above.
