MSI Z170a Carbon wont recognize RAM slots 1 and 2

Stephen_142

Prominent
Feb 17, 2017
1
0
510
Hi, i have a MSI z170a Carbon running a
Gen 7 I7 7700k, (Has GEN 7 bios update)
msi 470 RX 8gb
Cooler master V1000
Water cooled.. Master liquid pro120

only slots 3 and 4 work running Rip Jaw V 2400 ddr4.
Slots 1 and 2 wont boot the computer. I get DDRAM and CPU LED flashing on M/B when all 4 slots are filled.

HELP!!