Added RAM, PC won't boot (tried some things already)

Hello

I wanted to add some RAM to my system, but after adding the new RAM my PC won't boot (it won't even post to BIOS). I tried some things on my own (which I will describe below) but I can't get it to work...

Specs of the RAM:

old RAM: CM3X2048-1600C9DHX: 2x2Gb 1600MHz 9-9-9-24 1.8V

new RAM: CMX4GX3M2A1600C9: 2x2Gb 1600MHz 9-9-9-24 1.65V

I bought some new RAM that was as close to my old one (couldn't find any exact matches). The only thing that I can find that is different is the voltage, but I read that that wasn't that big of a deal.

I had them installed in alternating order (old, new, old, new), but my PC wouldn't even post to BIOS. When I boot with both RAM sticks the diagnostic LEDs show the following message: "System Power ON: The D-LED will hang here if the processor is damaged or not installed properly."

When I boot with either only the old, or only the new, my system boots fine and runs like it is supposed to.

I've tried some settings in the BIOS (I even tried these settings: http://forum.corsair.com/forums/showthread.php?p=388805), I've tried undervoltage (1.65V), I've tried overvoltage (1.8V), but none of these help.

I've even tried disconnecting my DVD-drive and my soundcard (if it would be some freaky thing with my power supply), but to no avail

Anyone have any ideas? I would really appreciate it :)

It is probably a case of one kit doesn't like the secondary timings and/or the voltage of the other. The ICs used on these two kits probably were produced many years apart and have very little in common, so that is to be at least somewhat expected.

Have you tried running them together at reduced speed of DDR3-1066? You have to manually set the memory clock with either one installed before adding the second kit. At the lower speed both kits should be able to run at the standard voltage of 1.5V.

Unfortunately, situations like yours are why we recommend to never mix memory from different kits. Sometimes, you end up with a combination that simply won't work. You will most likely need to buy a single kit of memory with 2 x 4GB modules.

If you have not tried it yet, make sure you have the most recent BIOS.

Yeah, I figured that this was a no-go :(

I'm just going to buy another 2x2 of the same new RAM...it's a shame, because I specifically picked the 2x2 instead of the 2x4 for budget reasons, now it's going to turn out more expensive.

I tried the 1066, same result

Make sure you try the most recent BIOS if you have not already.

It was a good suggestion, but it still gave the same result.. I'm just going to go and buy some more RAM...

Thanks for the help everybody :)