I have Lenovo M91P 7052-b5u i5-2400 (spec sheet) with 2+1 GB RAM
Because I have 4 sockets, I decided to add 2 more.
Yesterday I added Kingston 4+2 GB RAM 99u5471, but the PC didn't boot. It was black screen - no POST.
I thought maybe the new RAM wasn't compatible - but after I took out the old 2+1 RAM, everything worked just fine.
So right now the PC boot only if I putting OR only the old RAM OR only the new RAM but not both of them.
What can cause this? Is it because the size is different? (the Kingston is smaller than the old ones)
(I already tried to switch between the sockets)