Lexmark T420 Service Manual - Page 23

4048-00x 1. General Information The Lexmark™ T420(n) laser printer is a monochrome laser printer designed for single users or small workgroups. There are two models: • The T420 Base printer, with 16MB of memory standard, a parallel port, and a USB port. • The T420 Network printer, with 32MB of memory standard, an integrated Ethernet adapter, a parallel port, and a USB port. The purpose of this chapter is to provide an overview of the capabilities of the printer and available options for each of the T420 models. Note: Unless otherwise noted, all references to the Lexmark T420(n) laser printer are intended to refer equally to both the T420 Base and the T420 Network models. Maintenance Approach The diagnostic information in this manual leads you to the correct field replaceable unit (FRU) or part. Use the error code charts, symptom index, and service checks to determine the symptom and repair the failure. See "Diagnostic Information" on page 2-1, for the location of each section. See the "Repair Information" on page 4-1 to help identify parts. After completing the repair, perform tests as needed to verify the repair. Special Tools Long Phillips screwdriver (approximately 6-inch shank) Slotted screwdriver Small Phillips screwdriver When taking voltage readings, always use the printer frame as ground unless another ground is specified. General Information 1-1