Testing Memory

Procedure for troubleshootiing newly built systems

If you are building a brand new computer and some of the memory modules work in some of the slots, but not all of the memory modules will work, try the following procedure, after making sure that you are trying to use matching memory modules in the slot positions recommended by the motherboard manufacturer.

  1. Put one memory module in a slot that works, boot the computer, then see if there is a newer version of the UEFI available from the motherboard manufacturer’s website. If there is an updated version of the UEFI, download and install it. Make sure that the computer does not lose power during the UEFI upgrade as this could potentially make the system unbootable. You can minimise the risk by connecting the computer to an uninterruptible power supply if one is available.
  2. Remove all external power from the system then remove the CMOS battery and clear the volatile UEFI settings by using the ‘Clear CMOS’ jumper on the motherboard, assuming there is one. If there is no such jumper, you can simply leave the CMOS battery out of the system for several minutes or manually short-circuit the CMOS battery connections.
  3. After replacing the CMOS battery, load the safest possible UEFI settings, rather than the default settings or the optimised settings. Do not try anything clever like overclocking until the system works in a non-overclocked state. In fact, I would not recommend overclocking even when the system is up and running stably.
  4. Try turning down the speed at which you are trying to run the memory modules, in case one or more of them cannot actually run at its rated speed when installed in your particular motherboard.
  5. Remove all unnecessary hardware from the system to reduce the power consumption, just in case the memory problems are being caused by the power supply being overloaded.
  6. Boot the computer using a USB flash drive containing a UEFI-bootable copy of Memtest86 version 8.4, and follow the procedure below. If you can demonstrate that a component is faulty, ask your supplier as soon as possible to replace it.

Procedure for systems that support UEFI

  1. Boot the computer that has suspected memory problems using a USB flash drive containing a UEFI-bootable copy of Memtest86 version 8.4.
  2. If you see any failures, you may as well stop further testing straight away.
  3. In the case of a high-performance system, turn down the memory’s speed then run Memtest86 again.
  4. If there is more than one memory module fitted, try removing the one that seems to be faulty.
  5. Sometimes individual memory module slots on the motherboard become faulty, so try any apparently faulty memory module in another slot.
  6. Occasionally memory controller circuitry on the motherboard becomes faulty, in which case no memory module will work in any position.

Procedure for older systems

  1. Boot the computer that has suspected memory problems using Hiren’s Boot CD version 15.2.
  2. Run Memtest86+ version 4.30.
  3. If you see any failures, you may as well stop further testing straight away.
  4. In the case of a high-performance system, turn down the memory’s speed then run Memtest86+ again.
  5. If there is more than one memory module fitted, try removing the one that seems to be faulty.
  6. Sometimes individual memory module slots on the motherboard become faulty, so try any apparently faulty memory module in another slot.
  7. Occasionally memory controller circuitry on the motherboard becomes faulty, in which case no memory module will work in any position.