Dell Inspiron 1721 (Mid 2007) - Manual (Page 157)

Adding and Replacing Parts
157
3 Connect the appropriate antenna cables to the
WLAN card you are
installing:
If the WLAN card has two triangles on the label (white and black),
connect the white antenna cable to the connector labeled "main" (white
triangle), and connect the black antenna cable to the connector labeled
"aux" (black triangle).
If the WLAN card has three triangles on the label (white, black, and gray),
connect the white antenna cable to the white triangle, connect the black
antenna cable to the black triangle, and connect the gray antenna cable to
the gray triangle.
4 Secure unused antenna cables in the protective mylar sleeve.
5 Replace the cover and tighten the captive screws.
Removing a Mobile Broadband or WWAN Card
NOTE:
WWAN is also available on an ExpressCard (see "Using ExpressCards" on
page 77).
1 Follow the procedures in "Before You Begin" on page 135.
2 Turn the computer over.