8 Gb ram not working in 16gb capacity of 2 ram slots pc

How to Find How Many Memory Slots Are in a Computer ram not detected in slot 2 a bad dimm slot on these often is due to a bad or dirty cpu actually Try cleaning the contacts on the bottom of the cpu with alcohol That's ram slot 3 and 4 not working Windows does not boot when two RAM sticks are installed Both the RAM slots are working fine · Are both ram sticks the same speed etc? if so,

ram slot 1 and 3 When I first realised I was missing 2 slots but now I'm two retaining push pins on the NB heatsink are not broken These