- HP All-in-One Printer Manual

Q2431-90912 Chapter 5 Theory of operation 83
Tray 2, 500-, 1,500-sheet feeder media size detection
Media size in the cassette are detected by three switches. The switches are active after the
cassette is placed in the tray 2 feeder. (this also applies to the optional 500- and 1,500-sheet
feeder). The DC controller PCA microprocessor detects the size and presence of the media by
the combinations of the switches.
The tray 2 cassette can detect the media size using the switches describe above, however the
user can define the media size for the tray using the control-panel (see “Paper Handling menu”
on page 42). In this case the printer may not correctly detect the media size if the user’s defined
size does not match the tray settings.
To prevent a false size detection, the printer measures the time it takes for the media to pass
from its leading edge to its trailing edge and determines the media size that was fed from the
tray. When the measured size differs from the user’s defined size or from the media size
switches, a message will appear on the control-panel display (see “Alphabetical printer
messages” on page 258).
Table 32. Tray 2 and 500-sheet feeder media size switch settings
Paper size Media size switch setting
Upper Center Lower
No cassette installed
Off Off Off
A4
Off Off On
LTR
Off On Off
B5
Off On On
A5
On Off Off
EXE
On Off On
LGL
On On Off
UNV
On On On
Table 33. 1,500-sheet feeder media size switch settings
Paper size Media size switch setting
Upper Center Lower
No cassette installed
Off Off Off
A4
On Off On
LTR
Off On On
LGL
On On Off