My LG Tromm Dryer is approx. 5 years old. Currently the cooling light stays lit all the time and when I turn it off and on the "check filter" light comes on. I have cleaned the lint filter but I'm not sure what else to do. Someone said it may be the heating element. Someone else said it could be the control board. Im on tight budget and would like to do the repairs myself. Can anyone please help me??? Thank you!