Kush plants

It's my first time growing kush after growing autos,I've had to work away during the week quiet a bit and this misses was left to water and feed, I'm growin a afghan and a 8 ball..... She over feed them which caused some pretty bad nut burn but I couldn't go on to much to her as she didn't want me to grow while I was working away... She sed the timer has been a bit faulty and they where on for about 16 hours the other nite, this has now been sorted but I came home today to find the hairs have started to turn brown on them but the buds have not seemed to swell like I have seen with my autos in the past....is this due to the nut probs or light schedule fucking up??? I'm growin under 600w hps

Maybe a little of both, but more likely the nute problems. Pistils will turn brown before the calyx has matured if the nute problem happens at the wrong time and is serious enough. Or if it is a micronute problem, since the plant can't move them about so easily it affects the buds when NPK problems wouldn't.

Messing with the lights while in flower can cause major stress, which could also cause this. Just look after them and hope they recover...

Cheers buddy fingers crossed