Funny thing I learned about this recently. I also tried to install two Corsair RAM cards after taking both out, and it started up to nothing. I got it to work with one upgrade and one original. I went back again after starting it up, running it, accessing the internet and running a few programs and apps, and then I shut it down again and pulled the original card that was still in there and put the second Corsair back in there and tried again. This time it worked with both new cards. I suspect that the new cards are "blank" and need some kind of reference to sync with the system. Therefore, you have to install one with the original card already in there, boot it up so that it logs it in the system BIOS, and then once it has recognized and registered the system, you can pull the original and upgrade the second one. It should work fine after that. That was my experience anyway. Hope that helps.