RAM Troubleshooting with MemTest86+

About MemTest

Memtest86 is thorough, stand alone memory test for x86 architecture computers. BIOS based memory tests are a quick, cursory check and often miss many of the failures that are detected by Memtest86. Memtest86 was developed by Chris Brady with a first release in 1994. The advanced software MemTest86+ provides an up-to-date and completely reliable version of the software tool aimed at memory failures detection. The software is absolutely free, with no restrictions for private or commercial use.

Windows Installation

For Windows, installation begins by downloading either the Pre-Compiled Windows package to build a bootable floppy disk or an ISO (zip version) to create a bootable CD-ROM. After the file is downloaded an extract must be done to uncompress the file(s). To build a bootable floppy, go the folder where the files were extracted and click on the Install icon. The floppy disk will appear to be unformatted by Windows after the install is complete.

To build a bootable CD-ROM, use your CD burning software to create an image from the unzipped ISO file. Be sure to create CD from image. DO not simply copy the file to a CD.

Troubleshooting Memory Errors

Once a memory error has been detected, determining the failing SIMM/DIMM module is not a clear cut procedure. With the large number of motherboard vendors and possible combinations of memory slots it would be difficult if not impossible to assemble complete information about how a particular error would map to a failing memory module. However, there are steps that may be taken to determine the failing module. Here are four techniques that you may wish to use:

1) Removing modules.
This is simplest method for isolating a failing modules, but may only be employed when one or more modules can be removed from the system. By selectively removing modules from the system and then running the test you will be able to find the bad modules.

2) Rotating modules.
When none of the modules can be removed then you may wish to rotate modules to find the failing one. This technique can only be used if there are three or more modules in the system. Change the location of two modules at a time. For example put the module from slot 1 into slot 2 and put the module from slot 2 in slot 1. Run the test and if the failing bit or address changes then you know that the failing module is one of the ones just moved. By using several combinations of module movement you should be able to determine which module is failing.

3) Replacing modules.
If you are unable to use either of the previous techniques then you are left to selective replacement of modules to find the failure.

4) Avoiding allocation.
The printing mode for BadRAM patterns is intended to construct boot time parameters for a Linux kernel that is compiled with BadRAM support. This work-around makes it possible for Linux to reliably run with defective RAM.

Developers Website: http://www.memtest.org/

Downloading Links: http://www.memtest.org/#downiso