Placing a new SSD into a DVD caddy, the XPS do not start!
BUT, after the job, everything was right at the testing with closed Palm Rest. Replacing the screws for Palm Rest, NO MORE STARTING! Remove the screws, all is right!!!!!!!!!!!!!!
Replacing the screws one by one, I found one, which makes the trouble, near the small module connection with the motherboard, driving the upper Led row and the power button. I opened the Palm Rest again, and start the Laptop, but I could not shut down it, by the button, only by Windows. Since than the laptop won't start again...
The power button and it's wire is perfect. (D1 on the board???)