Printronix L1024, Maintenance Manual

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9–11 Chapter 9 – Controllers and Floppy Disk Drives
9.6.4 Troubleshooting
If you have not already done so, run the engine self-test. (Refer to the engine self-test information in
Chapter 13.)
If errors or other problems occur when running the engine self-test, then the problem is most likely not in
the Data Controller Board or the host computer. The problem, in this case, is more likely to be in the
Engine Controller Board, or in other areas of the printer engine. Refer to the troubleshooting information
in Chapter 13.
If the engine self-test runs with no errors, however, then 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.
If the printing diagnostic tests run correctly, the problem is most likely in the host computer. However, it
could also be in one of the following areas:
S
The Data Controller Board interface to the host computer (located on the Data Controller
Board).
S
The interface cables between the Data Controller Board and the host conputer.
S
A configuration mismatch between the printer and the host computer.
NOTE: If you suspect a configuration problem, refer to the Setup Guide for
instructions on properly configuring the printer. Refer to the documentation
for your host computer for information on configuring your host computer to
work with the printer.
If the printing diagnostic tests do not run correctly, or do not run at all, and the engine self-test ran
correctly, then the problem is most likely to be in the Data Controller Board, not the host computer. Run
the Data Controller Board power-up self-test, as described below.
Data Controller Board Power-Up Self-Test
Turn off power to the printer. When you turn the printer power back on, look through the three small round
holes located on the vertical rear panel of the Data Controller Board, and observe the three tiny green
LEDs mounted flat on the board. These LEDs serve as diagnostic indicators for the board’s power-up
self-test. The LEDs are identified as L1, L2, and L3, as shown in Figure 9–2. LEDs L1 and L2 display
information about the boot sequence. LED L3, described later, indicates CPU activity (or the lack of it) for
the microprocessor on the Data Controller Board.