Brother DCP6690CW Service Manual page 64

After the machine prints on the top face of the recording paper, the duplex print mechanism
(for duplex print models) (detailed on
switch the recording paper path and then drives the switchback roller (SB roller) to switch back
the recording paper (that has just been printed on its top face and ejected temporarily to the
duplex unit) toward the DX paper tray #1. This operation is called "switchback operation" and
the paper path through which the switchbacked paper (SB paper) advances is called
"switchback paper path." The SB paper in the DX paper tray #1 is fed again and printed on its
bottom face.
If a paper jam occurs in the switchback paper path, the user takes the DX paper tray #1 out of
the machine and opens the DX cover by pulling up the DX cover open levers (green in color)
provided on both sides in front of the duplex unit to remove the jammed paper.
After completion of duplex printing, the duplex print mechanism ejects the recording paper face
down so that the ejected sheets are automatically arranged in the document page order as shown
below. Even if the total number of pages is odd, the mechanism feeds and ejects the last sheet
for bottom-face printing.
Example: Ejection order of sheets when the total number of pages is odd
p. 4
p. 3
p. 2
p. 1
page 3-46) drives the DX flapper in the duplex unit to
Blank side
p. 5
3-10
Confidential