Computer boots with 3 ram but not 4

Computer won't start with RAM in certain slots ram slot 3 and 4 not working B550M DS3H ; 1 Solid Pin Power Connector ; 2 DVI ; 3 DisplayPort + HDMI ; 4 Realtek GbE LAN ; 5 Ultra Durable PCIe Slot · PCIe® Slot · Running 1* ram slot 1 and 3 or 2 and 4 If the RAM is not working, make sure the first thing you do is reseat the RAM Pop it out and push it back in · The next thing to do is check

rama 888 slot Or you can throw the mainboard against the wall Maybe the Ram falls out and goes into the