Testing loose RAM (removed from computer)

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Contents

Infrastructure

  • Several computers, each with one good stick of RAM in the lowest-address slot and access to a monitor and keyboard. Cases are left open. Each computer is labeled with the size of the stick of RAM it contains.
  • A paper chart converting common decimal byte counts to megabytes. The chart has, in its first (input) column a total count, including the size of the permanently attached working stick of RAM. In its second (output) column, it gives the amount of RAM excluding the permanently attached stick.

Justifications

  • Eventually we will eliminate the cases altogether, mounting motherboards and power supplies onto flat wood boards. Once configured to boot over Ethernet, the motherboards should function without keyboard. If we modify memtest86 to send data back through the Ethernet port instead of to the video screen, we will simultaneously eliminate the impetus to use a bank of monitors for RAM testing and also improve our ability to track testing results (errors displayed by memtest86 scroll off the screen and, AFAIK, there is no way to scroll back to see them) (However, there is always a way). Currently, because errors cannot be logged, RAM sticks must be tested individually. If we could collect errors in software, we could also identify which sticks failed out of several being tested simultaneously on a motherboard.
  • A set of component testing stations could also be set up in a much more space efficient fashion through the use of a KVM switch.
  • In a beautiful world, the RAM testing platforms would use ZIF sockets. Otherwise we will have to replace the motherboards of the testing platforms every week or so. Motherboards aren't built with ZIF sockets for RAM, so we would have to build our own motherboards or to modify existing ones (are ZIF socket parts even available for modern RAM?).
  • The paper log serves 2 purposes: (a) it ensures that the size of the memory module isn't forgotten after 2 hours of letting the test run. (b) it gives us a usage count by which to estimate when the workstation's motherboard will next need replacing.

Instructions

  • Take 1 stick from the pile of RAM to be tested and insert it into the second socket of one of the workstations labeled "RAM testing".
  • Power up the workstation.
  • Check how much RAM the BIOS reports. Look up that number on the RAM size chart, then record, on the workstation's paper log, the size, in megabytes, of your stick of RAM.
  • Boot into memtest86. To select the "test memory" option on an ubuntu CD, press F6 as the livecd is booting, right after the blocky BIOS style text clears.
  • Let memtest86 run until pass 3 completes (a couple of hours).
  • Check whether any errors were reported (they are displayed in red),
  • Power down the workstation.
  • Remove the RAM stick being tested. If errors were reported, put the stick in the recycling pile. Otherwise, put it in the box of good RAM, in the bag of memory sticks whose label matches your stick's size.
=====addendum=====

====i used two working TRANSITIONARY mother board TEST units -those that supported both SD RAM sd-66 to sd-166 OR ddr(0)ram pc-1600 to pc-3400 -so either type could be tested if motherboard supported through bios/chipset (but sd ram getting rare and expensive now so less commonly used today -but still VERY valuable IF offered on e-bay)

====or same idea with TRANSITIONARY ddr (0)[pc-1600 to pc-3400] OR

ddr2  [pc-3200 up to pc-8400]Jackshimanoram motherboard

====dunno if ddr2 OR ddr3 [pc-8400 up to beyond pc-10666] mother boards exist-might