Backlit Keyboard on Latitude E6410

Bought my machine used, so it didn't come with a warranty. Was strapped for cash after my HP fried, and wanted something to use. Anyway, the backlight on the keyboard won't stay constantly on, like I'm used to. BTW..very disgusted with HP for 3 years. Voiced my opinion to my pc-savy son, and he said that Dell is the step child of pc's. So, naturally I expected tech support, out of warranty like I had in the past with my other machines. Nope! No such animal. was told umpre-emptily that they cannot help me. I'm like ***?

Hope you can help. Right now, said backliight is on, but don't know for how long. Thanks.