how can i fix my nokia 6300 its switch of itself ?

And 10 mins later gonna do the same thing. What the phone needs is a firmware update. not the one from the nokia website.
you need specialist tools: Jaf or Usf and have a good understand of nokia flash files.

Otherwise take it to your local phone repair guy.

www.themobilephonesurgery.com

Alex
August 2009

take the battery out for 5 mins

Adam
July 2009