If you have a problem with MemTest86 first check the forums and the list of known issues below, to see if a solution is already available. If you think there is a bug in the software please see the section below on bug reporting and gathering trace information and gather as much information as you can about the problem before contacting us.
Problem & Bug Reporting
To improve the quality of MemTest86, accurate reporting of problems and bugs
essential. Please carefully follow the instructions below to report problems.
In Version 4.1.0 a Boot Trace feature was added that provides a simple mechanism for troubleshooting of test failures by both technical and non-technical users. With the very large variety of computer hardware available it is impossible to test MemTest86 an all platforms and some incompatibilities exist causing failures. With trace information many of these faults may now be resolved.
Enabling Boot Trace - The boot trace feature is enabled with either a boot time option or an on-line command. However, most problems occur during startup so the boot option is the preferred method. All of the released images have a boot option to start the test with boot tracing enabled. When booting from a Linux system with LILO or GRUB add “btrace” to the boot options line. When Boot Trace is enabled two columns of trace information will be displayed one the bottom two thirds of the screen. The CPU, line number from the source file, a short message and two parameters are displayed in each trace point. A “>” character denotes the current trace point. A total of 26 trace points are displayed and older trace points are lost as execution progresses. Pressing any key will advance to the next trace point. As initialization proceeds other portions of the screen will be filled in with information and the header lines will be erased.
Gathering Trace Information – There are two types of failures where trace information is needed to help diagnose the problem, hangs and crashes. Gathering traces for a situation when the test hangs is very simple. Just continue to press return until the test stops. At minimum email the last 5 trace points. More useful would be a digital picture of the screen. For cases where the test crashes we need to find the trace points just before the crash. This requires slowly stepping through the traces and identifying the point where the test crashes or reboots. Then run the test again and stop at the trace point just before the crash and report the information. Again, email at least the last 5 trace points or better a picture of the screen. Please email failure information using the form below.
Using Trace Information - Technical users will be able to diagnose problems using trace data that previously would have required detailed understanding of MemTest86's internal workings. By following the trace points in the source you will be able to follow the path of execution and identify problems. As needed new trace points may be added to the code to provide more detail when diagnosing a problem.
Additional Information - It is also very valuable to know how failures affect different releases. Please try each of the test versions provided and report. A number of failures affect only operation when multiple CPUs are being used. Please run using the option to run with only one CPU and report.
Sometimes when booting from a floppy disk the following messages scroll up on the screen:
X:8000 AX:0212 BX:8600 CX:0201 DX:0000
This is the BIOS reporting floppy disk read errors. Try re-writing the disk. If that does not work replace the disk.
MemTest86 can not diagnose many types of PC failures. For example a faulty CPU or motherboard that causes Windows to crash will most likely just cause MemTest86 to crash in the same way.
Often the memory works in a different system or the vendor insists that it is good. In these cases the memory is not necessarily bad but is not able to operate reliably at high speed. Sometimes more conservative memory timings on the motherboard will correct these errors. In other cases the only option is to replace the memory with better quality, higher speed memory. Don't buy cheap memory and expect it to work reliably. On occasion "block move" test errors will occur even with name brand memory and a quality motherboard. These errors are legitimate and should be corrected.
MemTest86 supports all types of memory. If fact the test has no knowledge of the memory or CPU type nor does it need to. MemTest86 is able to test all types and brands of memory. If the information reported regarding chipsets or CPU's is incorrect it will not affect testing in any way. This not a problem or bug but is listed here due to the many questions about this issue.
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