Try cleaning the lint screen....as in, scrubbing it with soap and a scouring pad. Just removing the obvious lint build up isn't all that's there. Run water through it. If the water pools on the screen then you have residue from dryer sheets, fabric softner, detergent, etc. That'll slow your air flow. Make sure the vent line in the wall is clear. Easiest test I do is hold a piece of paper over the drum vent, where the lint screen is, while pushing the door switch so the unit runs and if the paper sucks into the vent then your good. If you have week suction then you have poor air flow and need to clean your vent line. In the end you may need to replace your thermo fuses.