ATT 5840 Base reset code/procedure
Try this to get it working.
Relocate the handset(s) closer to the main base.
Check for any lights on the base including charge, intercom, and channel lights (if applicable to the model).
Re-cradle the handset on the base for 15 seconds. Lift the handset and press PHONE.
Unplug the AC adapter from the main base unit and take out the battery from the handset. Leave it unplugged for 15 seconds. Plug the handset battery in and re-cradle the handset. Plug back the AC adapter in and wait for 15 seconds.
Try to de-register the handsets by following the steps below:
1. Using the soft keys on the base located below the base screen, press MENU
2. Press the down arrow once until BASE SETTINGS is highlighted.
3. Press the OK soft key.
4. On the base, press MUTE 3 times and FLASH twice. This will
deregister the unit.
Below are steps on how to re-register the handsets:
1. Make sure to charge the handset battery pack at least 12 hours.
2. Using the soft keys on the base located below the base screen, press MENU.
3. Use the up or down arrow keys to select DISPLAY BASE ID.
4. Press OK. The base screen will display the 15-digit Base ID
code for about 30 seconds, then the unit returns to the idle
screen. Write down the Base ID code on a piece of paper.
5. At the cordless handset, use the soft key to select NEW.
6. Enter the 15-digit Base ID code using the number keypad.
7. Use the soft key to select OK. The screen displays PLEASE
8. After about 45 seconds, the screen displays FOUND BASE. If the handset displays BASE BUSY TRY LATER, the base is in
Other products that use the 5.8GHz band can interfere with the use of this phone. These products or equipments include: radio towers, page towers, cellular Phones, other 5.8GHz cordless phones, intercoms, or monitors. If any of these are in the area, they may interfere with the performance of the phone. Try relocating the phone.
Video displays, Televisions or Personal Computers can cause
interference on the phone if it is plugged in electrically with one of this equipment (typically on a power strip or extension cord). Please relocate the phone to an AC outlet without any other major appliance plugged in.
You can also relocate the base to another room.
Relocate the phone out of the kitchen area. Appliances may cause interference.
If the charge light does not remain on, clean the handset and base charging contacts using a pencil eraser. If it comes on after cleaning the contacts, you may need to charge the unit for 10 hours.
Make sure that the AC power cord is securely plugged into the base. If unsuccessful, plug the unit into a different known working outlet or turn on the switch on the power strip.