It sounds like you've tried all the troubleshooting steps we would have asked you to try. Please send an email to Intel Customer Support (http://www.intel.com/support/mailform/desktop/nuc/emailsupport.htm) for further assistance.
When requesting warranty replacement, you will need to include the following information:
- NUC model
- Serial number and SA Number (found on a barcode label on the bottom of the chassis)
- Shipping information
- Phone number
- Email address
Please also reference this community thread for the warranty agent to review.
Just one other thing before you email Customer Support. When you tried booting up with no memory modules in the system, did you see the "3-blink" pattern that would be expected:
- Three 1.0 second blinks.
- Then a 2.5-second pause (off).
- Then the entire pattern repeats until the system is powered off.
Is the pattern you described different than the "3-blink" memory issue pattern?