M2N-SLI Deluxe motherboard won't boot

This is what I would recommend doing to figure out whats going on:

Open the computer and run the mother board with only the necessary hardware. For example disconnect the cd drives , remove all the RAM except for one chip. See if that has any affect on the system starting.

Your description says its not booting, I am not sure if you mean booting as in to Windows , or booting as in not even powering up. If it is not powering up verify that the power supply is functioning (if you don't have a tester swap it out with another power supply).

There are a couple of other things you can do...below I inserted a flow chart for that. This diagram is great to follow for hardware issue's....I would definitely give that a try!

Also like I said above , by your description of " wont boot at all " I am assuming you mean hardware....if you were implying that Windows was not booting up , please let me know so I cna asist you further.....hope this helps straighten up your issue!