Printronix L1024, Maintenance Manual

Page: 279 / 372

13–7 Chapter 13 – Troubleshooting Guide
Preliminary Steps
By following these two steps, you will pinpoint the source of the problem more quickly and make
troubleshooting much easier and faster.
1. Engine Self-Test
Running the printer engine self-test can help isolate a problem to the printer engine, the
Engine Controller Board, the Data Controller Board, or the host computer. The self-test printout
consists of solid vertical lines (feedlines) every 1/16 inch running the entire length of the page
and over the full width of the page.
a. Press the small button on the Engine Controller Board, accessible through the small round hole
in the left side of the plastic Bottom Cover. This prints one test page. If you hold the button in,
the printer prints continuously until the button is released. Remember that after you push the
button, if the fuser is not up to its normal operating temperature, there might be a delay while
the fuser heats, before the printer starts printing.
b. If the engine self-test runs with no errors, the Data Controller Board or host computer is
probably at fault. Run one of the Data Controller Board printing self-tests. These tests are
accessible from the Diagnostics menu, using the Control Panel keys. (Refer to the
Setup
Guide for instructions on accessing and running these tests.) Running a printing self-test will
isolate the error to either the Data Controller Board or the host computer. For further help in
troubleshooting Data Controller Board and host computer problems, refer to the Data
Controller Board troubleshooting section in Chapter 9,
Controllers and Floppy Disk Drives.
c. If errors or other problems occur when running the engine self-test, continue with the following
steps.
2. Isolation Procedure Using the Engine Self-Test
a. Stop a test print in the middle of a page by turning off the printer or opening the top cover.
Remove the OPC drum and check to see if the error is showing on the developed image on
the OPC drum.
Turning off the printer during operation leaves the developed image on the OPC drum. If the
printer is allowed to operate until the print cycle is complete, the OPC drum is cleaned and
there is no developed image.
b. If the error is not apparent in the developed image on the OPC drum, check the unfused page
between the OPC drum and the Fuser.
If the error is present on the unfused page, the Transfer Charger is the source of the error. If
the error is not present on the unfused page, the Fuser is the source of the error.
c. If the error appears on the OPC drum, block the laser beam at the LSU cover glass and repeat
step 2a above.
If the error is still apparent on the OPC drum, the LSU is not the source of the error and the
Developer Unit and OPC Drum Unit must be checked.
If the error is not on the OPC drum, the LSU is probably the source of the problem.
d. If the error is well defined on the OPC drum with the laser beam blocked, the source of the
error is most likely the OPC Drum Unit or its power source.
e. If the error occurs on a large portion of the page, the OPC Drum Unit, the Developer Unit, or
the High Voltage Power Supply (H.V.P.S.) may be the source of the error.