how can i find out why my ghds dont work anymore?

hi all, hope you can help, my ghds have stopped working i've had them for 2 years now with no problem no warranty left on them, when i try to turn them on, no light no heat nothing. as i'm a girl i have checked the fuse and that works, i've taken them apart to see if a wire had come lose but they seem fine, i would like to know if there was a way of finding out how to mend them without any extra cost, any ideas? your responses will be greatly appreciated.