I have a Roper clothes dryer. It has to run through 2 cycles to dry clothes. My husband and I took it apart and cleaned it thouroughly and also replaced the thermostat. It did well on the next load, but now it won't dry. What else might it be? We have checked the breaker and the voltage, all is well. We can also feel that it is blowing out hot air where it is vented to the outside of the house (we also replced the vent piping) Do I need a new dryer?