USRobotics V.34 - Manual (Page 192)

COURIER HIGH SPEED MODEMS
G-10 Additional Operations
6. Locate the voice/data switch at the front of the modem.
Lift up and remove the modem (printed circuit board),
carefully easing the voice/data switch out of its opening in
the front panel.
7. Turn the modem rightside up and locate jumper switches J4
and J6, near the power-adapter socket. Use Figure G-1 as a
guide.
Figure G-1   Courier Modem Board
8. The jumpers are black shunts that cover two out of three
upright metal contacts. As shown in the figure, set the
jumpers so they cover the two contacts on each switch that
are closest to the front panel. The third contact on each
switch is exposed.
9. Replace the modem in the case top: ease the voice/data
switch into the opening in the front panel and make sure the
back of the board rests on the locator pins at the rear (from
which you removed the screws).