I have HP 20-r013w All-in-One Desktop PC computer which has 4 GB RAM installed but the manual says that I could upgrade it up to 8 GB. There are two sockets for memory cards for this model. When I checked there is one 4GB memory card installed in one of the sockets (black colored) and the second one (white) was empty. So, I bought a second 4 GB memory card: Crucial 4GB Single DDR3 1600 MT/s (PC3-12800) CL11 SODIMM 204-Pin 1.35V/1.5V Notebook Memory Module CT51264BF160B which has all required parameters. Today I received the card and tried to place it in the second socket (white) and then the computer did not reboot. The same thing happens if the original memory card is placed in the white socket. There is no sound when I try to start the computer with a memory card in the second socket, just black screen. At the same time both cards work perfectly if located in the primary, black socket. Is there something wrong with the second socket or I should do something before placing a memory card in it. Thanks!