To connect the Durabrand CD2155 hi-fi system to other devices, follow these steps: 1. Identify the available ports on the back of the CD2155 hi-fi system. Common ports include AUX IN, LINE OUT, and SPEAKER OUT. 2. For connecting an external audio source, such as a smartphone or MP3 player, locate the AUX IN port on the back of the hi-fi system. Use an audio cable with a 3.5mm stereo plug on one end and the appropriate connector on the other end. Connect one end of the cable to the audio output of the external device and the other end to the AUX IN port of the hi-fi system. 3. To connect the hi-fi system to an external amplifier or receiver, locate the LINE OUT port on the back of the hi-fi system. Use an audio cable with the appropriate connectors on both ends. Connect one end of the cable to the LINE OUT port of the hi-fi system and the other end to the corresponding input on the amplifier or receiver. 4. If you want to connect external speakers to the hi-fi system, locate the SPEAKER OUT ports on the back of the hi-fi system. Connect the speaker wires to the corresponding positive (+) and negative (-) terminals on the hi-fi system and the speakers. Ensure that all connections are secure and properly inserted. Refer to the manual for any specific instructions or troubleshooting steps related to connecting the hi-fi system to other devices.