Lenovo THINKSTATION 4155 - Manual (Page 18)

6. If you have powered speakers with an ac power adapter:
F_LR
a. Connect the cable that runs between the speakers, if necessary. On some
speakers, this cable is permanently attached.
b. Connect the ac power adapter cable to the speaker.
c. Connect the speakers to the computer.
d. Connect the ac power adapter to the ac power source.
7. If you have unpowered speakers with no ac power adapter:
F_LR
a. Connect the cable that runs between the speakers, if necessary. On some
speakers, this cable is permanently attached.
b. Connect the speakers to the computer.
10 User Guide