Print Engine Troubleshooting; Verifying Image Processor Operation By Using The Test Pattern Generator - Tektronix Phaser 440 Service Manual

6
Troubleshooting

Print engine troubleshooting

Verifying image processor operation by using the Test Pattern Generator

6-2 Phaser 440 Color Printer
6. Following the drum reversal, the drum motor rotates the drum
forward for a quarter of a revolution to position the paper clamp
under the bail rollers. This prevents the bail rollers from forming
depressions in the drum.
7.
The READY LED then blinks while the image processor initializes.
Following initialization, the READY LED is on.
The print engine is initialized. The engine fan runs continuously while the
printer is on. The large thermal head fans runs during printing and while the
thermal head temperature is greater than 35
head fans run during printing or when the ambient temperature inside the
o
printer exceeds 40 C (104
This topic is a step-by-step procedure for systematically verifying particular
aspects of a printer's operation. Following this procedure should lead to the
cause of a printer's failure.
Instructions for using the Test Pattern Generator are provided in Appendix D
"Test Pattern Generator."
1. Attach the Test Pattern Generator to the printer's parallel port. The
Test Pattern Generator can be attached to the printer while the printer
is turned on.
2.
If the printer does not power up go to the later topic "Verifying power
supply operation" on page 6-3.
3. Observe that the READY light is on (not blinking). If it does not light,
go to the later topic "Verifying power supply operation" on page 6-3.
4.
Select any test pattern using the Test Pattern Generator's four DIP
switches and then press its print button.
5. After the print is made, remove the Test Pattern Generator.
If the printer prints a test pattern, then the printer's image processor board and
print engine are working correctly. The printer's problem resides with the host
computer-to-printer connection, or the host computer. Refer to the appropriate
topics in Chapter 3 "Verifying the printer and its hosts." (Note that since the
Test Pattern Generator prints only through the parallel port, the possibility also
exists that the hardware of any of the other hosts interface ports could be
non-functioning, and could be the source of the print failure. In this case, the
printer should be able to print from another port, except the non-functioning
port.)
o
C (95
o
F).
o
F). The two smaller thermal