I have a Samsung DV438AER dryer that is about 4 years old. Recently it stopped heating and I replaced the heating element, problem solved. Immediately afterwards it would start and heat normally, but on sensor dry it would turn off a few minutes into the cycle leaving clothes wet. I replaced the sensor but I still have the same problem with the dryer turning off a few minutes into its cycle. I have cleaned the ducts and ensured unrestricted air flow, but the problem remains. I've read online that the circuit board or even the drive motor may be the culprit. Everything works fine when using the manual timed dry setting. I have no idea what to check next, any ideas?