Dell Precision 7540 RAM upgrade failed - system stuck at BIOS

Hi! I've tried upgrading my Precision 7540 from it's base MTA 16GB 2666MHz ram to Samsung 64GB running at 3200MHz without luck. I replaced two original sticks with four new ones and the system initially booted. However after a while it froze and would never boot up again. Moreover, the laptop freezes in BIOS or gets stuck at the integrated memory test. I decided to test the new sticks one by one, by inserting them consecutively to slot A. None of them works, despite of restoring the BIOS defaults. Are there any know RAM compatibility issues for the 7540? Am I doing something wrong here?