My iPhone is dead after do this tutorial

You could have a cable that is not properly seated, or something damaged during manipulation.

Try first disconnecting then re-seating all the cables that attach to the board on the top, under and around the metal plate; and in the middle (the battery and the charging dock). Do it gently, in order not to break any connectors or any component around them.

If not seated properly, at least 3 of the above will make your iPhone not start or look like it is not restarting.

Then for good measure, let your iPhone charge using a known good wall charger and a known good cable for 15 minutes (to make sure your battery is holding a charge), then hard-reboot your iPhone and see - and tell us - what happens.

To hard-reboot: press & hold (Home Button + Power Button) together for 12 seconds then release, then if the iPhone did not restart yet, press once on Power Button.