Is there any chance you can test a different power supply?
Did you add any new hardware/software?
Is there fan activity?
I would also recommend checking the following link Troubleshooting No Boot Issues on Intel® NUC Products.
Thank you for your answer Amy,
I tested the power supply, it look like OK.
Fan activity is ZERO. No dust arround and inside, but it don't start. In same time it don't look like blocked.