I have a lenovo p50 i7-6700hq that has expandability up to 64gb with 4 sodimms. When i got the laptop it had 2x 8gb 2133hz samsung ddr4. I ordered 2 more sticks of killisre 8gb 2666, and when i installed them, the machine wouldn't post. Here is what Ive done so far to troubleshoot:
1) i added only 1 stick of killisre ram rather than 2 and the machine posted. I thought this might be because the one stick was defective, but i swapped them and the machine still posted. so both ram sticks are definately working.
2) i then thought maybe the socket was busted, so i switched which slot the single stick of killisre was seated in. But to my suprise the machine still posted, so this wasnt the problem either.
3) I then removed the samsung memory and seated both sticks of killisre memory in their place (total of 2), and the machine posted, after adding one stick of samsung memory the machine posted (total of 3), but adding the second samsung stick the machine wouldnt post (total of 4)
So it seems that no matter what orientation ive arrange the dimms, as soon as i add a 4rth module the machine wont post. The machine will only posted with a max of three modules. I even tried a 4gb stick of samsung ddr4 2133hz, 16gb crucial 2400hz dimm, and the same result.
I am at a loss of what to do, right now i am updating the bios to see if there's any chance that could be the issue. Any help or ideas i could try would be appreciated.
EDIT: Updating BIOS doesn't resolve the issue.