No Lights, No Sound On Power-Up; Verifying Main Board Cpu Operation; Verifying Print Engine Operation By Printing Its Startup Page - Tektronix PHASER 840 Service Manual

No lights, no sound on power-up

If the printer shuts down with the power switch still on, the printer may have
experienced a spurious over-current event. If the printer powers-up within
2 seconds, do nothing. If the printer powers-up after 6 seconds, the printer
power supply has auto-ranged to the 220 VAC setting. Remove the power cord,
wait 30 seconds, then reinstall the power cord. The printer should power-up at
its 110 VAC setting within two seconds. If it does not, replace the power supply.
If the fans "twitch" and the LEDs flash, there may be a short in the power
supply system. Refer to the later procedure "Testing for shorted drivers" on
page 62.
If the fans do not move and the LEDs do not flash, there is either no AC power
to the printer or the power supply has failed. Check the AC voltage. If replacing
the power supply does not correct the problem, refer to the later procedure
"Testing for shorted drivers" on page 62.

Verifying main board CPU operation

1. If the printer does not power up (rear fan is off and power-up
diagnostic LEDs are off), go to the topic, "Verifying power supply
operation" on page 60.
2. Observe the rear panel LEDs located on each side of the rear panel DIP
switches. The left LED represents the operation of the PostScript firmware.
The right LED represents operation of the main board's print engine firmware.
During the POST tests, the two LEDs toggle back and forth for each
successful pass through each DRAM test. A failure in the power on self
tests is indicated by the Phaser 840 printer's left rear panel LED (the PS
LED) flashing in a specific pattern of long and/or short flashes and
repeated indefinitely. On the Phaser 850 printer, the front panel Error
LED is also used. Other failures are indicated by the failure being
printed on the Startup Page.
After successful power-up, the right LED flashes at a regular "heartbeat" rate.
The front panel Ready light is turned on, the LCD is turned on and the display
provides warm-up progress.
Verifying print engine operation by printing its startup
page
1.
If not already on, turn on the printer. If the printer does not begin
initializing, go to the topic, "Verifying power supply operation" below.
2.
Once the Power light is on (not blinking) and the front panel displays
Ready to Print, scroll to Menu and press Select. Then scroll to the
Printer Configuration menu item, press Select, and then scroll and
select the Startup Page menu item. The printer should print out a
Startup Page.
If the printer prints a Startup Page, then the print engine is working correctly. If
the printer does not print a Startup Page, then a problem exists with the print
engine.
Service Guide
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