Lenovo X240 wont power on / wont turn on / not powering up...

When push the power button the bib for the motherboard and keyboard lights turn on for a few seconds but screen does not power up, the led of the power button still green, and the fan cooling is running, nothing else.
I had already tried everything; remove battery, ram, plug, push buttons 30 and 60segs, reset button, change SSD, Change Ram, and nothing happen to my notebook. In the middle time I had to buy a new one, because even from the support of Lenovo itself I didn't get any answer to my problem.

Please somebody can help me whit the diagnose and possible solution.
Thanks in Advance.