How to Deregister/Reregister my AT&T Marathon Mic?

The AT&T Marathon has been discontinued for a few years, but if you still have them, here's how to introduce a new microphone into the mix:

Note: The microphone should be out of the base for de-registration and for the first 2 steps of registering the new mic.

DEREGISTRATION

1. Disconnect either the red Tel Wall Jack cord, or the orange Base Jack cord from charger base
2. Press and Hold the Pair button until the Mute light on the base blinks (then let go)
3. Press and release the Pair button (do not hold) while Mute is still flashing
4. ON/OFF on the headset button will turn orange and blue (this lets us know it’s deregistered)

QUICK FYI’s:

When you deregister a Marathon mic, the Lifter Mode light will blink on and off once (even if it’s in No Lifter Mode) after about 10 seconds to let you know deregistration was successful.

The lights on headset will go from blinking red and blue slowly to blinking red and blue quickly when attempting to pair with the base. If the lights start blinking slowly red and blue again, the registration did not go through (even if the mute light is still on).

Deregistering and re-registering a mic works best if you wait a full 10 seconds after the Lifter Mode light blinks before starting the registration process. Going too quickly often causes the headset not to pair.

REGISTER A NEW MIC

1. Disconnect either the red Tel Wall Jack cord, or the orange Base Jack cord from charger base
2. Make sure the headset’s battery is installed. If the headset is red as it sits on the charger, it needs to charge. If it hasn’t charged at all yet, charge it for 4 hours before trying these steps.
3. Press and hold the Pair button until the Mute light on the base comes on solid.
4. Put headset on the base while Mute light is solid. The ON/OFF button on the headset will turn blue (this lets us know it's registered).
5. If the ON/OFF button is still red, the headset may need to continue charging. Take it off the base and press the ON/OFF button on the headset. If the mode light on the base begins to flash the headset is registered and just needs to charge. If the mode light does not flash the headset is not registered. Repeat the registration steps.
6. Reconnect the red Tel Wall Jack cord or the orange Base Jack cord to base.
7. If the registration was not successful the ON/OFF button will flash twice every 5 seconds.

Time for a new headset?

Many AT&T Marathon Customers have made the switch to the Leitner LH270!