Troubleshooting Procedures - Sun Microsystems SPARCstation 4 110 Service Manual

4
C H A P T E R

Troubleshooting Procedures

This chapter describes how to troubleshoot SPARCstation 4 system problems. Each
problem is described, and a set of procedures is provided as a solution to the
problem.
No Video Output on the System Monitor
Power-On Does Not Succeed
Disk Drive Errors
Determining Faulty DSIMM Locations
TABLE 4-1
TABLE 4-1
Problem
LED on front of system is not lit.
Disk drive fails to boot or does
not respond.
Operating system does not
recognize disk drive at boot up.
No video output on monitor.
describes commonly encountered problems, and tips for solving them.
Troubleshooting Tips
Action
Verify that the power switch is turned on and that the power cord is
connected. If both the power switch and the power cord are connected,
shut down the system and verify that the LED cable is connected. If the
LED cable is connected, the power supply may be defective. Replace the
power supply. See Chapter 8.
Shut down the system. Verify the following NVRAM parameters: diag-
switch?=false, auto-boot?=true, and boot-dev=disk (see
TABLE 2-1 on page 2-5). The SCSI controller may be defective. See
Section 4.3.1 "Verifying the Built-In SCSI Controller" on page 4-6. Verify
that each SCSI device is assigned a unique SCSI target address. See
Appendix C, for important additional information.
Shut down the system. Verify that each SCSI device is assigned a unique
SCSI target address. See Appendix C, for important additional
information.
Verify that the power cord is connected. Use a volt-ohmmeter (VOM) to
check voltages. See Section 4.1 "No Video Output on the System Monitor"
on page 4-2.
4-1