OK, well while I do a little research to see what (if any) options Dell might have provided to recover your machine, I'd like you to see if your computer will boot from a Linux distro, because if it will then it's likely (but not 100% guaranteed) that your problems are not hardware related.
If you go to this topic in the Public Library here at MWR ... viewtopic.php?p=618146#p618146
... you'll find instructions for how to create a bootable copy of Puppy Linux on a USB stick. You'll also find instructions for how to boot your computer using it.
Let me know if you're able to boot into Linux or not. No need to backup any files at this point, just see whether Linux will boot.