My college age daughter bought a used dryer. AFter hooking it up it shut off after 5-10 minutes running. She took it back to the person she bought it from and he supposedly fixed it. Again after 5-10 minutes it permanently shut off. Her roommate said the dryer was very hot. She lives in an apartment building and had the maintenance person check both times to make sure the vents where clear. They confirmed that. What else could it be?