I have an old pc that has a motherboard called "Pegatron IPM31" with two slots for ddr2 ram, an intel celeron processor, and 1GB ram-800. I got another 1GB-667 for it, and here is what happens: - If I use the old ram in any of the two slots, no problem. - If I use the New ram in any of the two slots, the PC powers up, nothing on screen (But not with errors like if no ram or ram damaged). - If I use both, the PC powers up, OS boots, everything is okay except that bios & OS recognize only 1GB ram.

Please note:

  • Memtest+, CPU-Z, and similar tools recognize that the each slot has 1GB ram with 2048 MB total throw DOS, or even on Windows!!

  • The new ram works fine in other PCs.

  • I searched over the internet, and I found some guys talking about ram voltage, but there is nothing in this bios setup like this!!

  • No bios update can be found.
  • Removed the Cmos battery >> nothing changed.


Bios doesn't recognize ram

Make sure sure your memory is compatible with the following:

  • Dual channel, 2 slots, Non-ECC, 240-pin DDR2, Un-buffered
  • Types: 667/PC2-5300, 800/PC2-6400

Source IPM31 Motherboard layout reference


I can't find the detailed manual for this device (especially not in English), but is the new chip ranked differently than the old chip? Single ranked DIMMs usually only have memory chips on one side of the module, and with dual ranked the chips are on both sides. It may be that this board doesn't support dual ranked modules.

  • Both are dual sided – Ahmed Abdelhameed Mar 26 '15 at 11:48
  • I'm stumped unless the new one is quad ranked (two rows on each side). There is something about this RAM that the board doesn't like. From what little I did find about the board, both of those RAM speeds should be supported. – GuitarPicker Mar 26 '15 at 13:48
  • Yes, that's what I found too!! – Ahmed Abdelhameed Mar 26 '15 at 14:21

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