dimm2

At first I used a 8GB ram from Team Dark Black ddr4 (2 x 4GB 3000) inserted into ram slot 4(dimm4) and 2 (dimm2), and I have two more extra slots which are dimm3 and 1. Problem starts when I add another 8 GB ram from Viper ddr4 (2x4GB 3000)to those free slots. Now my PC won't turn on and there...