Laptop wont turn on

I have a Dell Inspiron 3543 and it will not turn on! It beeps when I try, in 3s, over and over. I have tried taking the battery out and unplugging it and pressing the power button for 10, 20, 30 seconds, I have tried pressing it 10, 20, 30 times. I tried pressing F2 and F10 and F12....Tried everything forums have told me and still it is not working. I don't know what else I can do. My warranty ran out in July 2016 and I can not afford the computer repair places. I do a lot of work on my computer!! Please someone help me!