Dell 5230DN, Service Manual

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Service Manual
Media level sensing
The media level for the media tray assembly is triggered by the actuator flag positioned in the two
photointerrupter sensors in the pick arm bracket assembly. The actuator flag blocks and unblocks the two
sensors in different sequence; it determines whether the paper tray is empty, low, or full.
Note: Media level sensing through sensor blocking sequence
Pick arm assembly
Since all media trays are functionally equivalent in terms of the switch (media size), sensor (media empty),
sensor (media low), only the components of one tray are described here.
The pick arm assembly is a mechanical unit supplying media from the media tray assembly to the printer. The
driving force, from the pick arm drive motor on the pick arm assembly, is transmitted to the two pick rolls to feed
media.
When the pick rolls pick up media, the remaining media decreases, and the media out actuator will lower and
interact with the sensor (media low) and sensor (media empty) to determine the amount of media remaining.
250-sheet tray Sensor A Sensor B
Tray full unblocked unblocked
Tray low blocked unblocked
Tray empty blocked blocked
550-sheet tray Sensor A Sensor B
Tray full unblocked blocked
Tray low blocked blocked
Tray empty blocked unblocked
Sensor (media low)
Media out actuator
Pick roll assemblies
Sensor (media empty)