Health Led; Media Tray Type Sensing; Tray Switch Sensor Combinations - Tektronix Z740/N - Phaser 740 Color Laser Printer Service Manual

Health LED

A health LED indicates the status of the image processor board. The health LED is
mounted on the image processor board and is viewable through a small hole in the
rear panel. Once the PostScript code is loaded into memory and the image processor
is initialized and running, the image processor blinks the LED at a one-second rate.
Blinking (at a steady rate): The printer is operating normally. The LED
blinks irregularly during power-up self-diagnostics.
If a soft error occurs, the image processor board operates, but at a reduced
capacity. Soft failures include failure of expansion memory DIMMs or any
of the interface ports. When a soft error occurs, the printer automatically
prints a startup page listing the error.
On or Off: A hard error condition has occurred that would keep the image
processor board from operating.

Media tray type sensing

The combinations of the three tray sensors "tell" the print engine what type of tray is
installed. The tray sensors are located on the left-side interior of the paper tray slot.
Sensor actuators are attached to the bottom end of the tray to close the appropriate
sensor. There are six tray types:
Letter (A-size) paper
Letter (A-size) transparency film
Metric Letter (A4-size) paper
Metric Letter (A4-size) transparency film
Legal-size paper
Auto-duplex unit

Tray switch sensor combinations

Left switch Middle switch
Closed Open
Closed Closed
Open Open
Open Closed
Open Closed
Closed Open
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Phaser 740 Color Printer
Right switch Tray type
Open Letter (A-size) paper
Open Letter (A-size) transparency film
Closed Metric Letter (A4-size) paper
Closed Metric Letter (A4-size) transparency
film
Open Legal size paper
Closed Auto-duplex unit