Dell 4100/200, 4100/180 manual Error Messages, RAM Test Group, Subtests, Why Run a RAM Test?

Table 5-2. System Diagnostics Tests (Continued)

Test
Groups	Subtests	Description
SCSI	Internal Diagnostic	Tests SCSI host adapters and all the SCSI devices
Devices	Seek Test	attached to them. Also can be used to remove CDs and
	Read Test	tape cartridges from SCSI devices and to display
	Write Test	information about the types of SCSI devices installed
	Audio Output Test	and the resources allocated to them.
	Eject Removable Media
	Display Information

NOTE: For the full name of an abbreviation or acronym used in this table, see the abbreviation and acronym list.

Error Messages

When you run a test group or subtest in the diagnostics, error messages may result. These particular error mes- sages are not covered in this chapter because the errors that generate these messages can be resolved only with Dell technical assistance. Record the messages on a copy of the Diagnostics Checklist found in Appendix A, and see Chapter 11, “Getting Help,” for instructions on obtaining technical assistance and informing the support technician of these messages.

RAM Test Group

The RAM Test Group subtests check all the directly addressable RAM.

Subtests

Three subtests are available for RAM: the Quick Mem- ory Test, the Comprehensive Memory Test, and the Cache Memory Test. The Quick Memory Test performs an address check to determine whether the computer is properly setting and clearing individual bits in RAM and whether the RAM read and write operations are affecting more than one memory address location at one time.

This subtest checks all available RAM. The Comprehen- sive Memory Test also performs an address check, as well as the following:

•Data pattern checks, to look for RAM bits that are stuck high or low, short-circuited data lines, and some data pattern problems that are internal to the memory chips

•A parity check that verifies the ability of the memory subsystem to detect errors

•A refresh check, to verify that the dynamic RAM (DRAM) is being recharged properly

The Cache Memory Test confirms the functionality of the computer’s cache controller chip and the cache memory.

Why Run a RAM Test?

Faulty memory can cause a variety of problems that may not, at first glance, appear to be happening in RAM. If the computer is displaying one or more of the following symptoms, run the subtests in the RAM Test Group to verify that the memory is not at fault:

•A program is not running as usual, or a proven piece of software appears to malfunction and you confirm that the software itself is not at fault. (You can confirm that the software is functioning properly by moving it to another computer and running it there.)

Running the System Diagnostics 5-11