Sun Microsystems SPARCstation 4, Service Manual

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4-1
C H A P T E R
4
Troubleshooting Procedures
This chapter describes how to troubleshoot SPARCstation 4 and SPARC Xterminal 1
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” on page 2
■
“Power-On Does Not Succeed” on page 3
■
“Disk Drive Errors” on page 5
■
“Determining Faulty DSIMM Locations” on page 7
TABLE 4-1
describes commonly encountered problems, and tips for solving them.
TABLE 4-1
Troubleshooting Tips
Problem Action
LED on front of system is not lit. 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.
Disk drive fails to boot or does not
respond. (Applies only to the
SPARCstation 4 system.) 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.” Verify that
each SCSI device is assigned a unique SCSI target address. See
Appendix C for important additional information.
Operating system does not recognize
disk drive at boot up. (Applies only to
the SPARCstation 4 system.) Shut down the system. Verify that each SCSI device is assigned a
unique SCSI target address. See Appendix C for important
additional information.
No video output on monitor. 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.”