How to Reset a DCX3400
The Motorola DCX3400 is part of the series of set-top receiver boxes designed for use with the Comcast Cable service. The DCX3400 has a number of programmable features and functions available for its users, like the setting of favorite channels or broadcast record scheduling. Each function that is programmed into the memory of the DCX3400 can be individually adjusted or reset. However, if you want to reset all of the DCX3400 functions back to the factory settings, the process to do so is fairly straightforward.
Press the "Menu" button on the DCX3400 remote control to open the main menu on your television.
Use the "Up/Down" arrow buttons to scroll to the "Advanced" option in the menu; then press the "Enter" button.
Scroll to the "System Reset" option; then press the "Enter" button. A warning prompt will appear asking if you want to return to the factory settings for the receiver. Press the "Enter" button.