You need to repot or deal with it. You've got that plant cramped. Which in turn is probably causing you some lockout issues.

I suggest repotting. Cutting off all the browned tips and monitoring it.

What size is that pot? It looks like a 3 gallon pot. I would suggest transplanting into a 5 gallon pot and leave it there until you harvest in about 6-8 more weeks.
daihashi Reviewed by daihashi on . 4 & 1/2 weeks flowering all leaves seem to be dying HELP!! Please does anyone know what is happening with my plant i am a first time grower its 4 and half weeks in flowering and the leaves are starting to go brown at every tip and how do i know when it is ready to start flushing???:(:stoned::( Rating: 5