root failed phone wont turn on

[bkz finest]

Hello im from Australia I purchased a note 3 from Telstra but its unlocked due to me being through optus pre paid, I rooted my phone awhile ago and never had no issues then I accidently clicked on something in the root I should off and its screwed my phone hasn't turned on in the last 2 months just comes up black screen and white writing Samsung note 3 and freezes on that some one please help as I would like to reset my phone to use it again

 

[ade_tobat]

Have u try to unroot the phone?

 

[bkz finest]

how do I do that it?
doesn't let me do anything?

 

[Rukbat]

Find a stock ROM at SamMobile Firmwares and flash it. You can boot into download mode, right?