Tablet boots to Samsung logo than the 2 led buttons flashes 3 times an

[FIXED] As the title says, the tablet boots to the Samsung logo then the 2 led buttons flashes 3 times and It shuts down.

If i connect It to the PC It shows up when it's off but (obviously) not while booting, then It "fails" to boot and It shows back again. [idk of this Is helpful]

How can i reach likes the download mode? the buttons combination doesnt work...

Please help, thanks

I have solved the problem.