
Oftentimes, the CPU cooler gets tightened too much in a corner or side, which can throw the CPU out of level so all the pins don’t make full contact, and that can result in an error. Your CPU cooler may not be installed correctly. If that’s the case, first try loosening the CPU cooler, then snugging it back down, but not overly tight. If both show up and the full amount of DRAM appears in one combination but not the other, then the one that doesn’t show may be bad, or the MC might be bad. If the memory modules are in slots one/three, try them in one/two and see what you have, and then try them in three/four.

It could be a bad channel on the motherboard or the memory controller (MC) located in the CPU. If you determine it’s a single bad slot, then it’s time to RMA the motherboard. Some motherboards show a preference for one set of slots or the other. If they were in slots one/three, then try them in two/four. Pull the modules and blow out the slots with compressed air. If you have another set of DRAM available, try those. If both boot up the rig, then move to he next suggestion. Check each DIMM individually to ensure it can boot the system by itself. Q-Tips or cotton swabs can leave fibers on the contacts. I suggest using foam swabs and isopropyl alcohol (rubbing alcohol). This can have a number of causes: You may have a bad DIMM. For example, it may show only one DIMM even if two are installed, or it may be showing both but only half the amount of DRAM that it should. Ensure that it’s showing the full amount of DRAM installed.

Your manual should show the correct slots for the DRAM. The memory modules may not be in the proper slots.
