Question Desktop won't reach POST after installing new RAM

[DDenis02]

Hi!
I just bought two new sticks of RAM (2x4GB) because I want to upgrade from 8GB to 16GB. The 2 sticks that I initially had work perfectly together, even though they are from different brands.
After installing the 2 new sticks of RAM, my pc won't reach post, won't even get a display signal from the video card. Everything is seated properly and there is no damage to the sticks or to the DIMMs on my MoBo because I checked each individual DIMM and stick. The motherboard is a Dell Optiplex 7010 SFF. The new sticks are identical to one I had before, so 3 of the sticks are identical (Zeppelin 4GB DDR3 1600Mhz) and the 4th one is a Kingston 4GB 1600Mhz. I even tried just the Zeppelin sticks but same thing. The problem appears only when 3 or 4 sticks are at the same time in the PC.
Things I tried:
-reset CMOS
-reset BIOS to default settings
-try each stick of RAM in each DIMM and in every combination possible (3 or 4 at the time)

Specs:
CPU - Intel i5-2500k
MoBo - Dell Optiplex 7010
GPU - GTX760

Thanks!

 

[SamirD]

The newer memory modules may be using higher density memory than the Dell supports. I would also try just the 2x new modules and see if they won't work by themselves. If they don't, then it confirms that they are not compatible.

 

[DDenis02]

The newer memory modules may be using higher density memory than the Dell supports. I would also try just the 2x new modules and see if they won't work by themselves. If they don't, then it confirms that they are not compatible.

The 2 new modules do work by themselves. Every combination of 2 modules work, the problem starts when there are 3 or 4 modules installed.