HP Designjet L25500 Series - Introduction; Safety precautions

Using this Manual
Purpose
This Service Manual contains information necessary to test, calibrate and service:
• HP Designjet L25500 42-inch Printer (Model CH955A)
• HP Designjet L25500 60-inch Printer (Model CH956A)
For information about using these printers, refer to the corresponding User Guide or Maintenance and
Troubleshooting Guide.
Chapters
1 Printer Systems
Use this chapter as a reference for technical information about the subsystems, components and how they
work together
Of particular importance are the diagrams included for each subsystem of the printer. They can be useful
for both troubleshooting and disassembly.
2 Troubleshooting
Whenever a printer is not functioning correctly due to a fault, use the Troubleshooting chapter for step-by-
step diagnosis until you arrive at the solution, which may include replacing a part.
Troubleshooting always begins with one of those two problems, so when you enter the chapter, navigate
to the proper section and find the troubleshooting steps for the problem you have found.
This chapter does not cover the procedures for the diagnostic tests you must perform while troubleshooting,
or the replacement procedures you must complete to fix the problem.
3 System Error Codes
This chapter contains the system error codes which are displayed on the Front Panel and EWS. Each
system error code shown in the chapter has a brief description and the steps required to solve the error.
Most of the troubleshooting steps involve performing a test or a calibration, which can be found in the
following chapter, before replacing any part that you suspect of causing the system error code, always
perform, the test or calibration.
4 Tests, Utilities, and Calibrations
Use this chapter whenever you need to perform a diagnostic test, service utility, or service calibration. This
chapter is meant to provide procedures and relevant information, not troubleshooting information. For
troubleshooting information, navigate to the Troubleshooting chapter.
These procedures are described in full, so that you know any relevant values for the test, as well as
information about what the printer is actually doing during the test.
The goal of diagnostic tests is to locate the root cause of the problem and the corresponding system error
code or message that will provide you with logical steps to resolution.
Some diagnostic tests or calibrations must be performed after removing a component.
5 Print Quality (IQ Troubleshooting)
This chapter describes the image quality diagnostic procedures. Further troubleshooting information
based on the symptom of the issue can be found in the customer document Maintenance and
Troubleshooting Guide.