Two nights ago, my PC froze and wouldn't post after a restart. Spend a whole day to find out that it only boots fine if I remove 1 stick of RAM. Both sticks work but not together. The other thing is that only slot 3 on my Z270 Gaming Pro mobo works. 1,2 & 4 seems to be "dead". I tried bios update, xmp enabled, removing cmos battery, gpu, etc., and still wont boot if I insert both sticks of ram(they are set). Any different ideas are welcome!