I am sorry to hear you are having these problems with the unit.
Based on your description, IT does not seem to be a problem with the Intel ® graphics controller or the Nvidia one since the unit Is not able to boot.
My best recommendation is to verify and double check the connections, make sure the power supply is working fine and if possible test other memory stick to discard any hardware issue. Another good step is to test another processor in the computer.
If after testing this troubleshooting steps issue persists, I recommend you contacting the motherboard system manufacturer so they provide more troubleshooting steps in order to fix the unit.