Where do you enter the custom voltage?
And do you actually enter the 21?
7 - 7 - 7 - 21 - 1T
select 21 from the list just like for CL and others, or try +/- on the numpad, or try entering it yourself
As for the voltages I dont own your motherboard so i dont know exactly, try looking around for voltage menu and find DRAM voltage or something like that. Or just google DRAM voltage and your motherboard name and you should find it. but be careful with voltages 1.9 - 2.0 should be your maximum, search for your ram to see recomended voltage