Service manual

106 Theory of operation ENWW
Jam detection
The following mechanisms detect the presence of media and paper-feed conditions:
● top-of-page sensor (PS2305)
● delivery sensor (PS2301)
● reversed-paper sensor (PS501)
● automatic duplexer pickup paper sensor (PS503)
The CPU detects a jam by checking for the presence of media through sensors against the
timing stored in the CPU.
If the CPU determines a jam, it stops the print operation and notifies the formatter of a jam.
Pickup sensors
Pickup delay jam
This printer performs retry control to readdress any pickup delay jam that the pickup error
causes. Pickup operation is conducted a maximum of twice at all pickup sources except for the
automatic duplex feed unit.
If the top-of-page sensor (PS2305) cannot detect the media leading edge within a specified
period of time (T) the printer performs the pickup operation again. If PS2305 cannot detect the
media leading edge within the specified period of time (T), a jam is indicated.
● paper pickup from the tray1: T = approximately 2.5 seconds
● paper pickup from the cassette: T = approximately 3.0 seconds
● paper pickup from the paper feeder: T = approximately 4.4 seconds
● paper pickup from the automatic duplexer feed unit: T = approximately 4.5 seconds
Pickup stationary jam
A. When the WAIT period starts—a pickup stationary jam is assessed if the top-of-page sensor
detects media when the WAIT period starts.
B. During media feeding—a pickup stationary jam is assessed if the top-of-page sensor
(PS2305) does not detect the trailing edge of the media within 3.8 seconds after detecting
the leading edge.