Tektronix Phaser 840, Руководство по обслуживанию

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Service Guide 57
System power-up sequence
The following lists the chain of events that occur when you turn on a printer. You
can follow this list as one means of determining if the printer is operating
correctly. The exact chain of events depends upon where the printer “believes”
the printhead is positioned. The printer records in non-volatile RAM the last
known position of the printhead and the cap/wipe/purge assembly.
Power switch is turned on:
1. Power supply senses AC line voltage conditions (110 VAC or 220 VAC)
and enables DC voltages. If an overload occurs, the printer turns off
the DC supplies, giving a “blink” effect to the front panel LEDs.
2.
Low-level, power-on self-test (POST) diagnostics are performed. The
two status LEDs at the rear panel should toggle and the front panel
LEDs are turned on. The front panel display is blank. This test takes
from 4 to 15 seconds depending on installed RAM.
3.
If POST diagnostics pass, the front panel Error LED is turned off and
the front panel displays Tektronix logo while the mechanical
initialization checks are performed.
If an error is detected, the Phaser 850 printer flashes the front panel
Error LED with a repeating error code pattern as well as the rear panel
PS LED. On the Phaser 840 printer, the pattern is displayed only on the
rear panel PS LED (left side of the DIP switches).
4. The mechanical initialization is conditional on the initial position of the
printhead and cap/wipe/purge assembly. Two NVRAM parameters
are checked for the last known position.
If the printhead is in either the Locked or Print position:
a. The cap/wipe/purge motor is run to ensure that the cap/wipe/
purge assembly activates its home-position sensor.
If the printhead is in the cap/wipe/purge position:
a. The heaters in the printhead and cap/wipe/purge assembly are
activated, as a precaution, to melt the ink which may have cooled
and solidified, thus gluing the cap/wipe/purge and printhead
together. 10 minutes pass while the cap/wipe/purge assembly
heats up.
b. The printhead is tilted back.
c. The ink is allowed to drain from the cap/wipe/purge assembly.
d. The cap/wipe/purge assembly is lowered to its home position.
5. The process motor is activated to rotate the head tilt gear into its home
position. (If the printhead is in the locked position it will not tilt
forward.) The process motor also rotates all the rollers to their ready
positions, disengage the transfix roller, and lower the maintenance
drawer blade and wiper.