Recently purchased Inspiron 3891. I wanted to upgrade the ram. I know its currently 8GB & 4GB DDR4 3200 for total 12GB of ram.

I purchase 16x2GB DDR 2666 ram, when installing the new ram, I cannot get the pc to boot even to bios.

I can get PC to boot using 8GB and 16GB stick together but any combination using just 16GB stick (ie 1x16 or 2x16) will not work whatsoever. I have the 16gb in slot 1 and 8gb(it came with) slot 2 and it is able to boot.

Any suggestions? Normally I would install new RAM and clear CMOS but there isn't a cmos reset on this mobo.

Any help would be grateful. thank you!