Your dryer may be turning it self off due to not venting prop, listen the back of dryer has a flex pipe attached to it for venting, disconnect hose ,unplug dryer first, put your hand into dryer where you disconnect hose it may be clogged with lint, then put your hand in hose pull out lint build up, this is a fire Hansard when clogged!!!!!! Then follow same hose to where it vents out from house disconnect their also alway a problem in that area, 9times out of ten a lot of lint their , when done make sure, All hoses are put back on these vent any gas left from dryer just like your furnace vents ok please make sure you re attach hoses after cleaning, plus if you don't you will be dusting your house every day:-(. Your dryer if fairly new shuts it self off because it is not letting heat out of it do to clogging ok , if this does not work it mat be something with the timer, good luck hope I have beem of service to you !
Butchie , Shumard
February 2012