Try to set ALL voltages except vCore and vDRAM on AUTO for the first time. If it boots than you have to set another value for some of the voltages (probably VTT). If it doesn't boot thank try with other memory divider and other timings. Performance Enhance put on Normal. For 24/7 Expert mode doesn't mean anything. Those modes set up the memory sub-timings lower and gives boost only in Everest memory benchmark so "relax" your memory. CPU PLL voltage "have" to be on 1.8v. When you on air it's better to set it at 1.7-1.8v but when you go on subzero cooling than is good.